Functional studies of Ycf3: its role in assembly of photosystem I and interactions with some of its subunits

Article Article scientifique Article Functional studies of Ycf3: its role in assembly of photosystem I and interactions with some of its subunits eng 2001-12-01 2001-12-01 author Naver Helle Departments of Molecular Biology and Plant Biology, University of Geneva, 30, quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland 509523 author Boudreau Eric Departments of Molecular Biology and Plant Biology, University of Geneva, 30, quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland 110948 author Rochaix Jean-David Departments of Molecular Biology and Plant Biology, University of Geneva, 30, quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland 25289 Administration de la faculté des sciences (SIAD) 2731-2745 10.1105/tpc.010253 11752384 1040-4651 PMC139485 <p>The Ycf3 protein is essential for the accumulation of the photosystem I (PSI) complex and acts at a post-translationa level. The sequence of Ycf3 is conserved in cyanobacteria, algae, and plants and contains three tetratrico-peptide re? peats (TPR). TPRs have been shown to function as sites for protein-protein interactions. The mutations Y95A/Y96A Y142A/W143A in the second and third TPR repeats lead to a modest decrease of PSI, but they prevent photoau- totrophic growth and cause enhanced light sensitivity even though the accumulated PSI complex is fully functional. This phenotype can be reversed under anaerobic conditions and appears to be the result of photooxidative damage. A temperature-sensitive ycf3 mutant, generated by random mutagenesis of a conserved region near the N-terminal end of Ycf3, was used in temperature-shift experiments to show that Ycf3 is required for PSI assembly but not for its stabil? ity. Immunoblot analysis of thylakoid membranes separated by two-dimensional gel electrophoresis and immunopre- cipitations shows that Ycf3 interacts directly with the PSI subunits PsaA and PsaD, but not with subunits from other photosynthetic complexes. Thus, Ycf3 appears to act as a chaperone that interacts directly and specifically with at least two of the PSI subunits during assembly of the PSI complex.</p> Dewey 580 Dewey 570 43 Département de biologie moléculaire 161 45 Département des sciences végétales 163 false The Plant cell 13 12 486ec221-86c3-4fef-a768-6b9cb891fbf3 Article (Published version) Restricted Naver_TPC_2001132731.pdf 3298811 application/pdf d6d543ca1acd6eb1a865a9179b2f812e1da7c92a30c5e4e7ac8db844ccc22d4e restrictedAccess Faculté des sciences / Section de biologie / Département de biologie moléculaire Faculté des sciences / Section de biologie / Département des sciences végétales

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Functional studies of Ycf3: its role in assembly of photosystem I and interactions with some of its subunits	The Plant cell			2001	53	0

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