Site-specific mutations of the N-terminal threonines in the D1 protein affects photoautotrophic growth but not D1 protein stability in Synechocystis 6803.
The cyanobacterium Synechocystis 6803 was engineered to produce a D1 protein where one or more of the N-terminal threonines at positions 2, 3 and 4 were replaced by other amino acid residues. No phenotypic effects were found for the T2S or T2L mutations, whereas the T2V, T2L;T4V and T2V;T3V;T4V mutations resulted in reduced photoautotrophic growth rate and oxygen evolving activity. The mutant strain T2V;T3V;T4V exhibited an oxygen evolution activity that was only half of that for the wild-type strain. Despite of that, both accumulation and stability of the D1 protein in the thylakoid membrane appeared unaffected in the mutant.
Salih
G
G
Dept. of Biochemistry, Arrhenius Laboratories, Stockholm University, Sweden.
Jansson
C
C
D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development*; D004795:Enzyme Stability / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000235:genetics*; D045332:Photosystem II Protein Complex; D013912:Threonine / Q000235:genetics*
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D013912:Threonine