Conserved residues in Ycf54 are required for protochlorophyllide formation in Synechocystis sp. PCC 6803.

ABSTRACT: Chlorophylls (Chls) are modified tetrapyrrole molecules, essential for photosynthesis. These pigments possess an isocyclic E ring formed by the Mg-protoporphyrin IX monomethylester cyclase (MgPME-cyclase). We assessed the in vivo effects of altering seven highly conserved residues within Ycf54, which is required for MgPME-cyclase activity in the cyanobacterium SynechocystisSynechocystis strains harbouring the Ycf54 alterations D39A, F40A and R82A were blocked to varying degrees at the MgPME-cyclase step, whereas the A9G mutation reduced Ycf54 levels by ∼75%. Wild-type (WT) levels of the cyclase subunit CycI are present in strains with D39A and F40A, but these strains have lowered cellular Chl and photosystem accumulation. CycI is reduced by ∼50% in A9G and R82A, but A9

SUBMITTER: Hollingshead S 

PROVIDER: S-EPMC5317394 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature