CC-4834 rbcL-L290F mt- (68-4PP) (non-pf2 progeny used for genetic analysis)
$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 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