Histidine residue 252 of the Photosystem II D1 polypeptide is involved in a light-induced cross-linking of the polypeptide with the alpha subunit of cytochrome b-559: study of a site-directed mutant of Synechocystis PCC 6803
Language English Country Netherlands Media print
Document type Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.
PubMed
12160992
DOI
10.1016/s0005-2728(02)00243-8
PII: S0005272802002438
Knihovny.cz E-resources
- MeSH
- Cytochrome b Group chemistry MeSH
- Photosynthetic Reaction Center Complex Proteins chemistry metabolism MeSH
- Photosystem II Protein Complex * MeSH
- Histidine MeSH
- Molecular Sequence Data MeSH
- Mutagenesis, Site-Directed MeSH
- Protein Subunits MeSH
- Amino Acid Sequence MeSH
- Cyanobacteria metabolism MeSH
- Light MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Names of Substances
- cytochrome b559 MeSH Browser
- Cytochrome b Group MeSH
- Photosynthetic Reaction Center Complex Proteins MeSH
- Photosystem II Protein Complex * MeSH
- Histidine MeSH
- photosystem II, psbA subunit MeSH Browser
- Protein Subunits MeSH
Properties of the Photosystem II (PSII) complex were examined in the wild-type (control) strain of the cyanobacterium Synechocystis PCC 6803 and its site-directed mutant D1-His252Leu in which the histidine residue 252 of the D1 polypeptide was replaced by leucine. This mutation caused a severe blockage of electron transfer between the PSII electron acceptors Q(A) and Q(B) and largely inhibited PSII oxygen evolving activity. Strong illumination induced formation of a D1-cytochrome b-559 adduct in isolated, detergent-solubilized thylakoid membranes from the control but not the mutant strain. The light-induced generation of the adduct was suppressed after prior modification of thylakoid proteins either with the histidine modifier platinum-terpyridine-chloride or with primary amino group modifiers. Anaerobic conditions and the presence of radical scavengers also inhibited the appearance of the adduct. The data suggest that the D1-cytochrome adduct is the product of a reaction between the oxidized residue His(252) of the D1 polypeptide and the N-terminal amino group of the cytochrome alpha subunit. As the rate of the D1 degradation in the control and mutant strains is similar, formation of the adduct does not seem to represent a required intermediary step in the D1 degradation pathway.
References provided by Crossref.org
Electron microscopy in structural studies of Photosystem II
