CC-4832 rbcL-L290F mt+ (68-4PP) (original isolate)
$30.00
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