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Plant Physiol. Apr 1993; 101(4): 1189–1194.
PMCID: PMC160638

Thermal Instability of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase from a Temperature-Conditional Chloroplast Mutant of Chlamydomonas reinhardtii.


Mutant 68-4PP of Chlamydomonas reinhardtii has only 10% of the normal level of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) holoenzyme when grown at 35[deg]C. However, when grown at 25[deg]C, the amount of holoenzyme is greater than 35% of the wild-type level, and the purified enzyme has a reduced CO2/O2 specificity factor. These mutant characteristics result from a chloroplast mutation that causes leucine-290 to be replaced by phenylalanine within the Rubisco large-subunit protein. A nuclear mutation (named S52-2B) was previously identified that can suppress both the in vivo instability and reduced CO2/O2 specificity of the mutant enzyme. However, the effect of this nuclear mutation on the in vitro stability of the holoenzyme was not resolved. In the present study, purified Rubisco from mutant 68-4PP was found to be less thermally stable than the wild-type enzyme, and it had maximal carboxylase activity at a lower temperature. When incubated at 35[deg]C, the mutant enzyme lost carboxylase activity at a much faster rate than the wild-type enzyme. However, the nuclear S52-2B suppresor mutation improved the thermal stability of the mutant enzyme in all cases. These results indicate that structural changes in mutant 68-4PP Rubisco can account for its observed inactivation in vitro and degradation in vivo. Such structural alterations are alleviated by the function of a nuclear gene.

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Selected References

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  • Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. [PubMed]
  • Chen ZX, Chastain CJ, Al-Abed SR, Chollet R, Spreitzer RJ. Reduced CO2/O2 specificity of ribulose-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of Chlamydomonas. Proc Natl Acad Sci U S A. 1988 Jul;85(13):4696–4699. [PMC free article] [PubMed]
  • Chen ZX, Green D, Westhoff C, Spreitzer RJ. Nuclear mutation restores the reduced CO2/O2 specificity of ribulosebisphosphate carboxylase/oxygenase in a temperature-conditional chloroplast mutant of Chlamydomonas reinhardtii. Arch Biochem Biophys. 1990 Nov 15;283(1):60–67. [PubMed]
  • Chen ZX, Spreitzer RJ. Chloroplast intragenic suppression enhances the low CO2/O2 specificity of mutant ribulose-bisphosphate carboxylase/oxygenase. J Biol Chem. 1989 Feb 25;264(6):3051–3053. [PubMed]
  • Chen ZX, Yu WZ, Lee JH, Diao R, Spreitzer RJ. 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. 1991 Sep 10;30(36):8846–8850. [PubMed]
  • Houtz RL, Stults JT, Mulligan RM, Tolbert NE. Post-translational modifications in the large subunit of ribulose bisphosphate carboxylase/oxygenase. Proc Natl Acad Sci U S A. 1989 Mar;86(6):1855–1859. [PMC free article] [PubMed]
  • Knight S, Andersson I, Brändén CI. Crystallographic analysis of ribulose 1,5-bisphosphate carboxylase from spinach at 2.4 A resolution. Subunit interactions and active site. J Mol Biol. 1990 Sep 5;215(1):113–160. [PubMed]
  • Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. [PubMed]
  • Laing WA. Regulation of Soybean Net Photosynthetic CO(2) Fixation by the Interaction of CO(2), O(2), and Ribulose 1,5-Diphosphate Carboxylase. Plant Physiol. 1974 Nov;54(5):678–685. [PMC free article] [PubMed]
  • Portis AR., Jr Partial reduction in ribulose 1,5-bisphosphate carboxylase/oxygenase activity by carboxypeptidase A. Arch Biochem Biophys. 1990 Dec;283(2):397–400. [PubMed]
  • Spreitzer RJ, Al-Abed SR, Huether MJ. Temperature-Sensitive, Photosynthesis-Deficient Mutants of Chlamydomonas reinhardtii. Plant Physiol. 1988 Mar;86(3):773–777. [PMC free article] [PubMed]
  • Spreitzer RJ, Goldschmidt-Clermont M, Rahire M, Rochaix JD. Nonsense mutations in the Chlamydomonas chloroplast gene that codes for the large subunit of ribulosebisphosphate carboxylase/oxygenase. Proc Natl Acad Sci U S A. 1985 Aug;82(16):5460–5464. [PMC free article] [PubMed]
  • Spreitzer RJ, Mets L. Photosynthesis-deficient Mutants of Chlamydomonas reinhardii with Associated Light-sensitive Phenotypes. Plant Physiol. 1981 Mar;67(3):565–569. [PMC free article] [PubMed]
  • Spreitzer RJ, Ogren WL. Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6293–6297. [PMC free article] [PubMed]
  • Van Dyk TK, Gatenby AA, LaRossa RA. Demonstration by genetic suppression of interaction of GroE products with many proteins. Nature. 1989 Nov 23;342(6248):451–453. [PubMed]

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