Subategory:

Mutants

Description:

Using standard methods of directed mutagenesis and nuclear-gene transformation of rbcSΔ-T60-3 mt- (MUT-4690), an L66F substitution (CTG-TTC) in the Rubisco small subunit was created. This mutant was created to see whether an L66F substitution in the nuclear-encoded small subunit would mimic the biochemical defects that arise from an L290F substitution in the chloroplast-encoded large subunit. Like mutant rbcL-L290F (68-4PP), the rbcS1-L66F mutant has a temperature-conditional phenotype. It grows on minimal medium at 25 °C, but dies on minimal medium at 35 °C. L66F Rubisco also has decreases in CO₂/O₂ specificity and holoenzyme stability in vivo and in vitro. See also rbcS1-L66F pf2 mt+ (MUT-4737). This strain has been maintained with acetate medium in darkness to prevent selection for secondary mutations that may improve Rubisco function.

Species:

Chlamydomonas

Locus:

RBCS1

Chromosome:

2

Phenotype:

Requires acetate at 35 °C; temperature-conditional