Subunit Organization of a Synechocystis Hetero-Oligomeric Thylakoid FtsH Complex Involved in Photosystem II Repair

0389924 - MBÚ 2013 RIV US eng J - Článek v odborném periodiku
Boehm, M. - Yu, J. - Krynická, Vendula - Barker, M. - Tichý, Martin - Komenda, Josef - Nixon, P. J. - Nield, J.
Subunit Organization of a Synechocystis Hetero-Oligomeric Thylakoid FtsH Complex Involved in Photosystem II Repair.
Plant Cell. Roč. 24, č. 9 (2012), s. 3669-3683. ISSN 1040-4651. E-ISSN 1532-298X
Grant CEP: GA MŠMT(CZ) ED2.1.00/03.0110; GA ČR GBP501/12/G055
Institucionální podpora: RVO:61388971
Klíčová slova: photosystem II * FtsH metalloproteases * subunit
Kód oboru RIV: EE - Mikrobiologie, virologie
Impakt faktor: 9.251, rok: 2012

FtsH metalloproteases are key components of the photosystem II (PSII) repair cycle, which operates to maintain photosynthetic activity in the light. Despite their physiological importance, the structure and subunit composition of thylakoid FtsH complexes remain uncertain. Mutagenesis has previously revealed that the four FtsH homologs encoded by the cyanobacterium Synechocystis sp PCC 6803 are functionally different: FtsH1 and FtsH3 are required for cell viability, whereas FtsH2 and FtsH4 are dispensable. To gain insights into FtsH2, which is involved in selective D1 protein degradation during PSII repair, we used a strain of Synechocystis 6803 expressing a glutathione S-transferase (GST)-tagged derivative (FtsH2-GST) to isolate FtsH2-containing complexes. Biochemical analysis revealed that FtsH2-GST forms a hetero-oligomeric complex with FtsH3. FtsH2 also interacts with FtsH3 in the wild-type strain, and a mutant depleted in FtsH3, like ftsH2(-) mutants, displays impaired D1 degradation. FtsH3 also forms a separate heterocomplex with FtsH1, thus explaining why FtsH3 is more important than FtsH2 for cell viability. We investigated the structure of the isolated FtsH2-GST/FtsH3 complex using transmission electron microscopy and single-particle analysis. The three-dimensional structural model obtained at a resolution of 26 angstrom revealed that the complex is hexameric and consists of alternating FtsH2/FtsH3 subunits
Trvalý link: http://hdl.handle.net/11104/0218798