Chloroplast site-directed mutagenesis of photosystem I in Chlamydomonas: Electron transfer reactions and light sensitivity

Citation
Jd. Rochaix et al., Chloroplast site-directed mutagenesis of photosystem I in Chlamydomonas: Electron transfer reactions and light sensitivity, BIOCHIMIE, 82(6-7), 2000, pp. 635-645
Citations number
62
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHIMIE
ISSN journal
03009084 → ACNP
Volume
82
Issue
6-7
Year of publication
2000
Pages
635 - 645
Database
ISI
SICI code
0300-9084(200006/07)82:6-7<635:CSMOPI>2.0.ZU;2-B
Abstract
The photosystem I (PSI) complex is a multisubunit protein-pigment complex e mbedded in the thylakoid membrane which acts as a light-driven plastocyanin /cytochrome c(6)-ferredoxin oxido-reductase. The use of chloroplast transfo rmation and site-directed mutagenesis coupled with the biochemical and biop hysical analysis of mutants of the green alga Chlamydomonas reinhardtii wit h specific amino acid changes in several subunits of PSI has provided new i nsights into the structure-function relationship of this important photosyn thetic complex. In particular, this molecular-genetic analysis has identifi ed key residues of the reaction center polypeptides of PSI which are the li gands of some of the redox cofactors and it has also provided important ins ights into the orientation of the terminal electron accepters of this compl ex. Finally this analysis has also shown that mutations affecting the donor side of PSI are limiting for overall electron transfer under high light an d that electron trapping within the terminal electron accepters of PSI is h ighly deleterious to the cells. (C) 2000 Societe francaise de biochimie ct biologie moleculaire / Editions scientifiques et medicales Elsevier SAS.