From Robert J. Spreitzer, University of Nebraska, July 2014

R258-3B was recovered as a photosynthesis-competent revertant of rbcL-V331A mt+ (45-3B) (Chen and Spreitzer 1989; Chen et al. 1991). It results from intragenic suppression that causes an I393M substitution in the Rubisco large subunit (Satagopan and Spreitzer, unpublished). The double-mutant strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Chen Z, Spreitzer RJ (1989) Chloroplast intragenic suppression enhances the low CO2/O2 specificity of mutant ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 264:3051-3053

Chen Z, Yu W, Lee JH, Diao R, Spreitzer RJ (1991) Complementing amino-acid substitutions within loop 6 of the alpha/beta-barrel active site influence the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 30:8846-8850


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-25B1 mt+ (CC-4700) were used to create an L326I substitution (CTT-ATT) in the Rubisco large subunit, which causes a decrease in Rubisco holoenzyme stability (Zhu and Spreitzer 1996). This is the original mutant strain. It was created to investigate phylogenetic differences near large-subunit residue Val-331 (see rbcL-V331A) (Chen and Spreitzer 1989; Chen et al. 1991). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Chen Z, Spreitzer RJ (1989) Chloroplast intragenic suppression enhances the low CO2/O2 specificity of mutant ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 264:3051-3053

Chen Z, Yu W, Lee JH, Diao R, Spreitzer RJ (1991) Complementing amino-acid substitutions within loop 6 of the alpha/beta-barrel active site influence the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 30:8846-8850

Zhu G, Spreitzer RJ (1996) Directed mutagenesis of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase: Loop-6 substitutions complement for structural stability but decrease catalytic efficiency. J Biol Chem 271:18494-18498


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-25B1 mt+ (CC-4700) were used to create a V341I substitution (GTT-ATT) in the Rubisco large subunit (Zhu and Spreitzer 1996). This is the original mutant strain. It was created to investigate phylogenetic differences near large-subunit residue Val-331 (see rbcL-V331A) (Chen and Spreitzer 1989; Chen et al. 1991). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Chen Z, Spreitzer RJ (1989) Chloroplast intragenic suppression enhances the low CO2/O2 specificity of mutant ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 264:3051-3053

Chen Z, Yu W, Lee JH, Diao R, Spreitzer RJ (1991) Complementing amino-acid substitutions within loop 6 of the alpha/beta-barrel active site influence the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 30:8846-8850

Zhu G, Spreitzer RJ (1996) Directed mutagenesis of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase: Loop-6 substitutions complement for structural stability but decrease catalytic efficiency. J Biol Chem 271:18494-18498


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-25B1 mt+ (CC-4700) were used to create an M349L substitution (ATG-CTG) in the Rubisco large subunit (Zhu and Spreitzer 1996). This is the original mutant strain. It was created to investigate phylogenetic differences near large-subunit residue Val-331 (see rbcL-V331A) (Chen and Spreitzer 1989; Chen et al. 1991). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Chen Z, Spreitzer RJ (1989) Chloroplast intragenic suppression enhances the low CO2/O2 specificity of mutant ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 264:3051-3053

Chen Z, Yu W, Lee JH, Diao R, Spreitzer RJ (1991) Complementing amino-acid substitutions within loop 6 of the alpha/beta-barrel active site influence the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 30:8846-8850

Zhu G, Spreitzer RJ (1996) Directed mutagenesis of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase: Loop-6 substitutions complement for structural stability but decrease catalytic efficiency. J Biol Chem 271:18494-18498


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-25B1 mt+ (CC-4700) were used to create L326I (CTT-ATT) and M349L (ATG-CTG) substitutions in the Rubisco large subunit, which complemented for structural stability but decreased CO2/O2 specificity (Zhu and Spreitzer 1996). The L326I/M349L double mutant was created to investigate phylogenetic differences near large-subunit residue Val-331 (see rbcL-V331A) (Chen and Spreitzer 1989; Chen et al. 1991). After being maintained with acetate medium in darkness for several years, the original L326I/M349L double-mutant culture was found to contain only two types of mutant cells, both of which had additional mutations in the rbcL gene (Satagopan et al. 2000). L326I/V341I/M349L/A378T mutant cells had an acetate-requiring phenotype, and H310N/L326I/M349L cells had a wild-type phenotype. It was proposed that these additional substitutions may have been selected because they improve Rubisco holoenzyme stability (Satagopan et al. 2000). See also CC-4713 and CC-4714. Yvonne Arendsen in Spreitzer’s group created the rbcL-L326I/M349L mt+ mutant again in 2000, and that is the strain listed here. It has been maintained with acetate medium in darkness since it was created, but it has not been investigated for the presence of suppressor mutations.


Chen Z, Spreitzer RJ (1989) Chloroplast intragenic suppression enhances the low CO2/O2 specificity of mutant ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 264:3051-3053

Chen Z, Yu W, Lee JH, Diao R, Spreitzer RJ (1991) Complementing amino-acid substitutions within loop 6 of the alpha/beta-barrel active site influence the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 30:8846-8850

Satagopan S, Arendsen YJ, Spreitzer RJ (2000) Selection for improved Rubisco stability in the absence of photosynthesis. Plant Biology 2000:809

Zhu G, Spreitzer RJ (1996) Directed mutagenesis of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase: Loop-6 substitutions complement for structural stability but decrease catalytic efficiency. J Biol Chem 271:18494-18498


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, 2014

Phenotype: requires acetate, sensitive to light

This chloroplast mutant was isolated by screening a large collection of acetate-requiring mutants (Spreitzer et al. 1988) for lack of complementation (Spreitzer and Ogren 1983) with a known rbcL mutant. The mutant was crossed with pf2 mt- to confirm uniparental inheritance, and an mt+ progeny clone was analyzed (Thow and Spreitzer 1991; Spreitzer 1993). The mutant results from a GGT to AGT rbcL mutation that causes Gly-237 to be substituted by Ser in the Rubisco large subunit. The mutant strain has a decreased level of Rubisco holoenzyme and lacks carboxylase activity. Attempts to select photosynthesis-competent revertants yielded only true revertants (Spreitzer 1998). This strain has been maintained with acetate medium in darkness since its recovery.


Spreitzer RJ (1998) Genetic engineering of Rubisco. In JD Rochaix, M Goldschmidt-Clermont, S Merchant, eds, The Molecular Biology of Chloroplasts and Mitochondria in Chlamydomonas, Kluwer Academic Publishers, Dordrecht, pp 515-527

Spreitzer RJ, Ogren WL (1983) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777

Thow G, Spreitzer RJ (1991) Decreased accumulation of Rubisco due to a chloroplast rbcL mutation of Chlamydomonas. Plant Physiol 96:49

Spreitzer RJ (1993) Genetic dissection of Rubisco structure and function. Annu Rev Plant Physiol Plant Mol Biol 44:411-434


  • Locus:
  • rbcL, PF2
  • Chromosome:
  • chloroplast,11

From Robert J. Spreitzer, University of Nebraska, 2014

Phenotype: requires acetate, sensitive to light

This chloroplast mutant was isolated by screening a large collection of acetate-requiring mutants (Spreitzer et al. 1988) for lack of complementation (Spreitzer and Ogren 1983) with a known rbcL mutant. The mutant was crossed with pf2 mt- to confirm uniparental inheritance, and an mt- progeny clone was analyzed (Thow and Spreitzer 1991; Spreitzer 1993). The mutant results from a GGT to AGT rbcL mutation that causes Gly-237 to be substituted by Ser in the Rubisco large subunit. The mutant strain has a decreased level of Rubisco holoenzyme and lacks carboxylase activity. Attempts to select photosynthesis-competent revertants yielded only true revertants (Spreitzer 1998). This strain has been maintained with acetate medium in darkness since its recovery.


Spreitzer RJ (1998) Genetic engineering of Rubisco. In JD Rochaix, M Goldschmidt-Clermont, S Merchant, eds, The Molecular Biology of Chloroplasts and Mitochondria in Chlamydomonas, Kluwer Academic Publishers, Dordrecht, pp 515-527

Spreitzer RJ, Ogren WL (1983) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777

Thow G, Spreitzer RJ (1991) Decreased accumulation of Rubisco due to a chloroplast rbcL mutation of Chlamydomonas. Plant Physiol 96:49

Spreitzer RJ (1993) Genetic dissection of Rubisco structure and function. Annu Rev Plant Physiol Plant Mol Biol 44:411-434


  • Locus:
  • rbcL, PF2
  • Chromosome:
  • chloroplast,11

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

The 68-7AN chloroplast mutant was recovered by screening a collection of acetate-requiring mutants (Spreitzer et al. 1988) for lack of complementation with a known Rubisco rbcL mutant (Spreitzer and Ogren 1983). It results from an rbcL nonsense mutation that changes the codon for Gln-45 (CAA) to ocher (TAA) (Spreitzer 1993). It is not known whether this mutant may be suppressed by heteroplasmic informational (tRNA) suppression (see rbcL-W66Amber) (Yu and Spreitzer 1992). This is the original mutant strain. It has been maintained with acetate medium in darkness since its isolation.


Spreitzer RJ (1993) Genetic dissection of Rubisco structure and function. Annu Rev Plant Physiol Plant Mol Biol 44:411-434

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777

Spreitzer RJ, Ogren WL (1983) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Yu W, Spreitzer RJ (1992) Chloroplast heteroplasmicity is stabilized by an amber-suppressor tryptophan tRNA(CUA). Proc Natl Acad Sci USA 89:3904-3907


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

The 68-7AN chloroplast mutant was recovered by screening a collection of acetate-requiring mutants (Spreitzer et al. 1988) for lack of complementation with a known Rubisco rbcL mutant (Spreitzer and Ogren 1983). It results from an rbcL nonsense mutation that changes the codon for Gln-45 (CAA) to ocher (TAA) (Spreitzer 1993). It is not known whether this mutant may be suppressed by heteroplasmic informational (tRNA) suppression (see rbcL-W66Amber) (Yu and Spreitzer 1992). This strain was recovered from a cross between the original 68-7AN mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Spreitzer RJ (1993) Genetic dissection of Rubisco structure and function. Annu Rev Plant Physiol Plant Mol Biol 44:411-434

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777

Spreitzer RJ, Ogren WL (1983) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Yu W, Spreitzer RJ (1992) Chloroplast heteroplasmicity is stabilized by an amber-suppressor tryptophan tRNA(CUA). Proc Natl Acad Sci USA 89:3904-3907


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

The 68-7AN chloroplast mutant was recovered by screening a collection of acetate-requiring mutants (Spreitzer et al. 1988) for lack of complementation with a known Rubisco rbcL mutant (Spreitzer and Ogren 1983). It results from an rbcL nonsense mutation that changes the codon for Gln-45 (CAA) to ocher (TAA) (Spreitzer 1993). It is not known whether this mutant may be suppressed by heteroplasmic informational (tRNA) suppression (see rbcL-W66Amber) (Yu and Spreitzer 1992). This strain was recovered from a cross between the original 68-7AN mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Spreitzer RJ (1993) Genetic dissection of Rubisco structure and function. Annu Rev Plant Physiol Plant Mol Biol 44:411-434

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777

Spreitzer RJ, Ogren WL (1983) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Yu W, Spreitzer RJ (1992) Chloroplast heteroplasmicity is stabilized by an amber-suppressor tryptophan tRNA(CUA). Proc Natl Acad Sci USA 89:3904-3907


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

The 69-12Q chloroplast mutant was recovered by screening a collection of acetate-requiring mutants for lack of complementation with a known Rubisco rbcL mutant. It results from a T173I substitution (ACA-ATA) in the chloroplast-encoded large subunit of Rubisco, which eliminates carboxylase activity but not Rubisco holoenzyme assembly (Spreitzer et al. 1988). This active-site residue is normally Ile in Rhodospirillum rubrum Rubisco, and replacing that residue with Thr also causes a decrease in carboxylase activity (Chene et al. 1997). Selection for photosynthesis-competent revertants of rbcL-T173I yielded only true revertants (Spreitzer 1998). This strain has been maintained with acetate medium in darkness since its isolation.


Chene P, Day AG, Fersht AR (1997) Role of isoleucine-164 at the active site of Rubisco from Rhodospirillum rubrum. Biochem Biophys Res Com 232:482-486

Spreitzer RJ (1998) In JD Rochaix, M Goldschmidt-Clermont, S Merchant, eds, The Molecular Biology of Chloroplasts and Mitochondria in Chlamydomonas, Kluwer Academic Publishers, Dordrecht, pp 515-527

Spreitzer RJ, Brown T, Chen Z, Zhang D, Al-Abed SR (1988) Missense mutation in the Chlamydomonas chloroplast gene that encodes the Rubisco large subunit. Plant Physiol 86:987-989


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

The 69-12Q chloroplast mutant was recovered by screening a collection of acetate-requiring mutants for lack of complementation with a known Rubisco rbcL mutant. It results from a T173I substitution (ACA-ATA) in the chloroplast-encoded large subunit of Rubisco, which eliminates carboxylase activity but not Rubisco holoenzyme assembly (Spreitzer et al. 1988). This active-site residue is normally Ile in Rhodospirillum rubrum Rubisco, and replacing that residue with Thr also causes a decrease in carboxylase activity (Chene et al. 1997). Selection for photosynthesis-competent revertants of rbcL-T173I yielded only true revertants (Spreitzer 1998). This strain was recovered from a cross between the original 69-12Q mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Chene P, Day AG, Fersht AR (1997) Role of isoleucine-164 at the active site of Rubisco from Rhodospirillum rubrum. Biochem Biophys Res Com 232:482-486

Spreitzer RJ (1998) In JD Rochaix, M Goldschmidt-Clermont, S Merchant, eds, The Molecular Biology of Chloroplasts and Mitochondria in Chlamydomonas, Kluwer Academic Publishers, Dordrecht, pp 515-527

Spreitzer RJ, Brown T, Chen Z, Zhang D, Al-Abed SR (1988) Missense mutation in the Chlamydomonas chloroplast gene that encodes the Rubisco large subunit. Plant Physiol 86:987-989


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

The 69-12Q chloroplast mutant was recovered by screening a collection of acetate-requiring mutants for lack of complementation with a known Rubisco rbcL mutant. It results from a T173I substitution (ACA-ATA) in the chloroplast-encoded large subunit of Rubisco, which eliminates carboxylase activity but not Rubisco holoenzyme assembly (Spreitzer et al. 1988). This active-site residue is normally Ile in Rhodospirillum rubrum Rubisco, and replacing that residue with Thr also causes a decrease in carboxylase activity (Chene et al. 1997). Selection for photosynthesis-competent revertants of rbcL-T173I yielded only true revertants (Spreitzer 1998). This strain was recovered from a cross between the original 69-12Q mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Chene P, Day AG, Fersht AR (1997) Role of isoleucine-164 at the active site of Rubisco from Rhodospirillum rubrum. Biochem Biophys Res Com 232:482-486

Spreitzer RJ (1998) In JD Rochaix, M Goldschmidt-Clermont, S Merchant, eds, The Molecular Biology of Chloroplasts and Mitochondria in Chlamydomonas, Kluwer Academic Publishers, Dordrecht, pp 515-527

Spreitzer RJ, Brown T, Chen Z, Zhang D, Al-Abed SR (1988) Missense mutation in the Chlamydomonas chloroplast gene that encodes the Rubisco large subunit. Plant Physiol 86:987-989


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

Directed mutagenesis and chloroplast co-transformation of wild-type 2137 mt+ (CC-3269) were used to create an N123G substitution (AAC-GGC) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Zhu and Spreitzer 1994). This is the original mutant strain. It was created due to a previous study of Rhodospirillum rubrum Rubisco (Chene et al. 1992). The strain has been maintained with acetate medium in darkness since its creation.


Chene P, Day AG, Fersht AR (1992) Mutation of asparagine 111 of Rubisco from Rhodospirillum rubrum alters the carboxylase/oxygenase specificity. J Mol Biol 225:891-896

Zhu G, Spreitzer RJ (1994) Directed mutagenesis of chloroplast ribulose-bisphosphate carboxylase/oxygenase: Substitutions at large subunit asparagine 123 and serine 379 decrease CO2/O2 specificity. J Biol Chem 269:3952-3956


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

Directed mutagenesis and chloroplast co-transformation of wild-type 2137 mt+ (CC-3269) were used to create an N123G substitution (AAC-GGC) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Zhu and Spreitzer 1994). It was created due to a previous study of Rhodospirillum rubrum Rubisco (Chene et al. 1992). This strain was recovered from a cross between the original N123G mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Chene P, Day AG, Fersht AR (1992) Mutation of asparagine 111 of Rubisco from Rhodospirillum rubrum alters the carboxylase/oxygenase specificity. J Mol Biol 225:891-896

Zhu G, Spreitzer RJ (1994) Directed mutagenesis of chloroplast ribulose-bisphosphate carboxylase/oxygenase: Substitutions at large subunit asparagine 123 and serine 379 decrease CO2/O2 specificity. J Biol Chem 269:3952-3956


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

Directed mutagenesis and chloroplast co-transformation of wild-type 2137 mt+ (CC-3269) were used to create an N123G substitution (AAC-GGC) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Zhu and Spreitzer 1994). It was created due to a previous study of Rhodospirillum rubrum Rubisco (Chene et al. 1992). This strain was recovered from a cross between the original N123G mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Chene P, Day AG, Fersht AR (1992) Mutation of asparagine 111 of Rubisco from Rhodospirillum rubrum alters the carboxylase/oxygenase specificity. J Mol Biol 225:891-896

Zhu G, Spreitzer RJ (1994) Directed mutagenesis of chloroplast ribulose-bisphosphate carboxylase/oxygenase: Substitutions at large subunit asparagine 123 and serine 379 decrease CO2/O2 specificity. J Biol Chem 269:3952-3956


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

Directed mutagenesis and chloroplast co-transformation of wild-type 2137 mt+ (CC-3269) were used to create an S379A substitution (TCA-GCA) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Zhu and Spreitzer 1994). This is the original mutant strain. It was created due to previous studies of Synechococcus and Rhodospirillum rubrum Rubisco (Harpel and Hartman 1992; Lee and McFadden 1992). The strain has been maintained with acetate medium in darkness since its creation.


Harpel MR, Hartman FC (1992) Enhanced CO2/O2 specificity of a site-directed mutant of ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 267:6475-6478

Lee GJ, McFadden BA (1992) Serine-376 contributes to the binding of substrate by ribulose-bisphosphate carboxylase/oxygenase from Anacystis nidulans. Biochemistry 31:2304-2308

Zhu G, Spreitzer RJ (1994) Directed mutagenesis of chloroplast ribulose-bisphosphate carboxylase/oxygenase: Substitutions at large subunit asparagine 123 and serine 379 decrease CO2/O2 specificity. J Biol Chem 269:3952-3956


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

Directed mutagenesis and chloroplast co-transformation of wild-type 2137 mt+ (CC-3269) were used to create an S379A substitution (TCA-GCA) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Zhu and Spreitzer 1994). It was created due to previous studies of Synechococcus and Rhodospirillum rubrum Rubisco (Harpel and Hartman 1992; Lee and McFadden 1992). This strain was recovered from a cross between the original S379A mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Harpel MR, Hartman FC (1992) Enhanced CO2/O2 specificity of a site-directed mutant of ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 267:6475-6478

Lee GJ, McFadden BA (1992) Serine-376 contributes to the binding of substrate by ribulose-bisphosphate carboxylase/oxygenase from Anacystis nidulans. Biochemistry 31:2304-2308

Zhu G, Spreitzer RJ (1994) Directed mutagenesis of chloroplast ribulose-bisphosphate carboxylase/oxygenase: Substitutions at large subunit asparagine 123 and serine 379 decrease CO2/O2 specificity. J Biol Chem 269:3952-3956


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Phenotype: requires acetate, sensitive to light

Directed mutagenesis and chloroplast co-transformation of wild-type 2137 mt+ (CC-3269) were used to create an S379A substitution (TCA-GCA) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Zhu and Spreitzer 1994). It was created due to previous studies of Synechococcus and Rhodospirillum rubrum Rubisco (Harpel and Hartman 1992; Lee and McFadden 1992). This strain was recovered from a cross between the original S379A mt+ and pf2 mt-, and has been maintained with acetate medium in darkness since its isolation.


Harpel MR, Hartman FC (1992) Enhanced CO2/O2 specificity of a site-directed mutant of ribulosebisphosphate carboxylase/oxygenase. J Biol Chem 267:6475-6478

Lee GJ, McFadden BA (1992) Serine-376 contributes to the binding of substrate by ribulose-bisphosphate carboxylase/oxygenase from Anacystis nidulans. Biochemistry 31:2304-2308

Zhu G, Spreitzer RJ (1994) Directed mutagenesis of chloroplast ribulose-bisphosphate carboxylase/oxygenase: Substitutions at large subunit asparagine 123 and serine 379 decrease CO2/O2 specificity. J Biol Chem 269:3952-3956


  • Locus:
  • rbcL, PF2
  • Chromosome:
  • chloroplast,11

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-MX3312 mt+ (CC-4696) were used to create a D473A substitution (GAC-GCT) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Satagopan and Spreitzer 2004). This is the original mutant strain. It was created due to a previous study of the role of Asp-473 in catalysis (Duff et al. 2000). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Duff AP, Andrews TJ, Curmi PM (2000) The transition between the open and closed states of rubisco is triggered by the inter-phosphate distance of the bound bisphosphate. J Mol Biol 298:903-916

Satagopan S, Spreitzer RJ (2004) Substitutions at the Asp-473 latch residue of Chlamydomonas ribulosebisphosphate carboxylase/oxygenase cause decreases in carboxylation efficiency and CO2/O2 specificity. J Biol Chem 279:14240-14244


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-MX3312 mt+ (CC-4696) were used to create a D473E substitution (GAC-GAA) in the Rubisco large subunit, which causes a decrease in Rubisco CO2/O2 specificity but not holoenzyme stability (Satagopan and Spreitzer 2004). The x-ray crystal structure of the mutant protein has been solved (Karkehabadi et al. 2007). This is the original mutant strain. It was created due to a previous study of the role of Asp-473 in catalysis (Duff et al. 2000). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Duff AP, Andrews TJ, Curmi PM (2000) The transition between the open and closed states of rubisco is triggered by the inter-phosphate distance of the bound bisphosphate. J Mol Biol 298:903-916

Karkehabadi S, Satagopan S, Taylor TC, Spreitzer RJ, Andersson I (2007) Structural analysis of altered large-subunit loop-6/carboxy-terminus interactions that influence catalytic efficiency and CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 46:11080-11089

Satagopan S, Spreitzer RJ (2004) Substitutions at the Asp-473 latch residue of Chlamydomonas ribulosebisphosphate carboxylase/oxygenase cause decreases in carboxylation efficiency and CO2/O2 specificity. J Biol Chem 279:14240-14244


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-MX3312 mt+ (CC-4696) were used to create a Y190L substitution in the Rubisco large subunit, which causes small decreases in Rubisco carboxylation and holoenzyme stability (Esquivel and Spreitzer, unpublished). This mutant strain was created to investigate the molecular basis for crosslinking between Rubisco large and small subunits (Ferreira et al. 1996). Other nearby Tyr residues have been studied (Esquivel et al. 2006). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function or stability.


Esquivel MG, Pinto TS, Marin-Navarro J, Moreno J (2006) Substitution of tyrosine residues at the aromatic cluster around the betaA-betaB loop of Rubisco small subunit affects the structural stability of the enzyme and the in vivo degradation under stress conditions. Biochemistry 45:5745-5753

Ferreira RM, Franco E, Teixeira AR (1996) Covalent dimerization of ribulose bisphosphate carboxylase subunits by UV radiation. Biochem 318:227-234


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, July 2014

Directed mutagenesis and chloroplast transformation of rbcL-W66Amber mt+ were used to create a Y226L substitution (TAC-TTA) in the Rubisco large subunit, which causes decreases in Rubisco carboxylation and holoenzyme stability (Esquivel et al. 2006). This mutant strain was created to investigate Rubisco degradation. Other nearby Tyr residues have been studied (Esquivel et al. 2006). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function or stability.


Esquivel MG, Pinto TS, Marin-Navarro J, Moreno J (2006) Substitution of tyrosine residues at the aromatic cluster around the betaA-betaB loop of Rubisco small subunit affects the structural stability of the enzyme and the in vivo degradation under stress conditions. Biochemistry 45:5745-5753


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate at 35 °C, temperature-conditional

The 68-4PP chloroplast mutant was isolated by screening for temperature-conditional, acetate-requiring mutants (Spreitzer et al. 1988). It can grow on minimal medium at 25 °C, but dies on minimal medium at 35 °C. It results from an rbcL missense mutation that changes the codon for Leu-290 (CTT) to Phe (TTT), which causes a decrease in Rubisco CO2/O2 specificity and holoenzyme stability (Chen et al. 1988). The x-ray crystal structure has been solved (Karkehabadi et al. 2005). Selection for photosynthesis-competent revertants at the restrictive temperature has identified intragenic (R96-4C, R96-8E) and rbcS-intergenic (R88-5A, R116-1B, R116-10C) suppressors (Du and Spreitzer 2000; Du et al. 2000; Genkov et al. 2006). This is the original mutant strain. It has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function or stability.


Chen Z, Chastain CJ, Al-Abed SR, Chollet R, Spreitzer RJ (1988) Reduced CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 85:4696-4699

Du YC, Hong S, Spreitzer RJ (2000) RbcS suppressors enhance the CO2/O2 specificity and thermal stability of rbcL-mutant ribulose-1,5-bisphosphate carboxylase/oxygenase. Proc Natl Acad Sci USA 97:14206-14211

Du YC, Spreitzer RJ (2000) Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 275:19844-19847

Genkov T, Du YC, Spreitzer RJ (2006) Small-subunit cysteine-65 substitutions can suppress or induce alterations in the large-subunit catalytic efficiency and holoenzyme thermal stability of ribulose-1,5-bisphosphate carboxylase/oxygenase. Arch Biochem Biophys 451:167-174

Karkehabadi S, Taylor TC, Spreitzer RJ, Andersson I (2005) Altered intersubunit interactions in crystal structures of catalytically-compromised ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 44:113-120

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate at 35 °C, temperature-conditional

The 68-4PP chloroplast mutant was isolated by screening for temperature-conditional, acetate-requiring mutants (Spreitzer et al. 1988). It can grow on minimal medium at 25 °C, but dies on minimal medium at 35 °C. It results from an rbcL missense mutation that changes the codon for Leu-290 (CTT) to Phe (TTT), which causes a decrease in Rubisco CO2/O2 specificity and holoenzyme stability (Chen et al. 1988). The x-ray crystal structure has been solved (Karkehabadi et al. 2005). Selection for photosynthesis-competent revertants at the restrictive temperature has identified intragenic (R96-4C, R96-8E) and rbcS-intergenic (R88-5A, R116-1B, R116-10C) suppressors (Du and Spreitzer 2000; Du et al. 2000; Genkov et al. 2006). This strain was recovered from a cross between the original 68-4PP mt+ and pf2 mt-, and has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function or stability.


Chen Z, Chastain CJ, Al-Abed SR, Chollet R, Spreitzer RJ (1988) Reduced CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 85:4696-4699

Du YC, Hong S, Spreitzer RJ (2000) RbcS suppressors enhance the CO2/O2 specificity and thermal stability of rbcL-mutant ribulose-1,5-bisphosphate carboxylase/oxygenase. Proc Natl Acad Sci USA 97:14206-14211

Du YC, Spreitzer RJ (2000) Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 275:19844-19847

Genkov T, Du YC, Spreitzer RJ (2006) Small-subunit cysteine-65 substitutions can suppress or induce alterations in the large-subunit catalytic efficiency and holoenzyme thermal stability of ribulose-1,5-bisphosphate carboxylase/oxygenase. Arch Biochem Biophys 451:167-174

Karkehabadi S, Taylor TC, Spreitzer RJ, Andersson I (2005) Altered intersubunit interactions in crystal structures of catalytically-compromised ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 44:113-120

Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

R96-8E was recovered as a photosynthesis-competent revertant after methyl-methanesulfonate mutagenesis of rbcL-L290F mt+ (68-4PP) (Hong and Spreitzer 1997). It results from an intragenic-suppressor mutation that causes an A222T substitution (GCT-ACT) in the Rubisco large subunit, which increases the CO2/O2 specificity of the original mutant enzyme (Hong and Spreitzer 1997; Du and Spreitzer 2000). The L290F/A222T mutant-enzyme x-ray crystal structure has been solved (Karkehabadi et al. 2005). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Du YC, Spreitzer RJ (2000) Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 275:19844-19847

Hong S, Spreitzer RJ (1997) Complementing substitutions at the bottom of the barrel influence catalysis and stability of ribulose-bisphosphate carboxylase/oxygenase. J Biol Chem 272:11114-11117

Karkehabadi S, Taylor TC, Spreitzer RJ, Andersson I (2005) Altered intersubunit interactions in crystal structures of catalytically-compromised ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 44:113-120


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

R96-4C was recovered as a photosynthesis-competent revertant after methyl-methanesulfonate mutagenesis of rbcL-L290F mt+ (68-4PP) (Hong and Spreitzer 1997). It results from an intragenic-suppressor mutation that causes a V262L substitution (GTA-TTA) in the Rubisco large subunit, which increases the CO2/O2 specificity of the original mutant enzyme (Hong and Spreitzer 1997; Du and Spreitzer 2000). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Du YC, Spreitzer RJ (2000) Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 275:19844-19847

Hong S, Spreitzer RJ (1997) Complementing substitutions at the bottom of the barrel influence catalysis and stability of ribulose-bisphosphate carboxylase/oxygenase. J Biol Chem 272:11114-11117


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Using standard methods of directed mutagenesis and chloroplast-gene transformation of rbcL∆-25B1 mt+ (CC-4700), an A222T substitution (GCT-ACA) was created in the Rubisco large subunit (Du and Spreitzer 2000). This is the intragenic-suppressor substitution that complements the L290F substitution in photosynthesis-competent revertant R96-8E (rbcL-L290F/A222T) (Hong and Spreitzer 1997). The A222T substitution alone improves the thermal stability of wild-type Rubisco (Du and Spreitzer 2000). The x-ray crystal structure of L290F/A222T double-mutant Rubisco has been solved (Karkehabadi et al. 2005). This strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Du YC, Spreitzer RJ (2000) Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 275:19844-19847

Hong S, Spreitzer RJ (1997) Complementing substitutions at the bottom of the barrel influence catalysis and stability of ribulose-bisphosphate carboxylase/oxygenase. J Biol Chem 272:11114-11117

Karkehabadi S, Taylor TC, Spreitzer RJ, Andersson I (2005) Altered intersubunit interactions in crystal structures of catalytically-compromised ribulose-1,5-bisphosphate carboxylase/oxygenase. Biochemistry 44:113-120


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Using standard methods of directed mutagenesis and chloroplast-gene transformation of rbcL∆-25B1 mt+ (CC-4700), a V262L substitution (GTA-TTA) was created in the Rubisco large subunit (Du and Spreitzer 2000). This is the intragenic-suppressor substitution that complements the L290F substitution in photosynthesis-competent revertant R96-4C (rbcL-L290F/V262L) (Hong and Spreitzer 1997). The V262L substitution alone improves the thermal stability of wild-type Rubisco (Du and Spreitzer 2000). This strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Du YC, Spreitzer RJ (2000) Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 275:19844-19847

Hong S, Spreitzer RJ (1997) Complementing substitutions at the bottom of the barrel influence catalysis and stability of ribulose-bisphosphate carboxylase/oxygenase. J Biol Chem 272:11114-11117


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Directed mutagenesis and chloroplast transformation of rbcL∆-25B1 mt+ (CC-4700) were used to create a C256F substitution (TGT-TTC) in the Rubisco large subunit (Du et al. 2003). This is the original mutant strain. It was created to investigate phylogenetic differences near large-subunit residue Leu-290 (see rbcL-L290F) (Chen et al. 1988; Spreitzer et al. 2005). The strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.


Chen Z, Chastain CJ, Al-Abed SR, Chollet R, Spreitzer RJ (1988) Reduced CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 85:4696-4699

Du YC, Peddi SR, Spreitzer RJ (2003) Assessment of structural and functional divergence far from the large subunit active site of ribulose-1,5-bisphosphate carboxylase/oxygenase. J Biol Chem 278:49401-49405

Spreitzer RJ, Peddi SR, Satagopan S (2005) Phylogenetic engineering at an interface between large and small subunits imparts land-plant kinetic properties to algal Rubisco. Proc Natl Acad Sci USA 102:17225-17230


  • Locus:
  • rbcL
  • Chromosome:
  • chloroplast