The structure of photosystem II (PSII) complex isolated from thylakoid membranes of the red alga Porphyridium cruentum was investigated using electron microscopy followed by single particle image analysis. The dimeric complexes observed contain all major PSII subunits (CP47, CP43, D1 and D2 proteins) as well as the extrinsic proteins (33 kDa, 12 kDa and the cytochrome c(550)) of the oxygen-evolving complex (OEC) of PSII, encoded by the psbO, psbU and psbV genes, respectively. The single particle analysis of the top-view projections revealed the PSII complex to have maximal dimensions of 22 x 15 nm. The analysis of the side-view projections shows a maximal thickness of the PSII complex of about 9 nm including the densities on the lumenal surface that has been attributed to the proteins of the OEC complex. These results clearly demonstrate that the red algal PSII complex is structurally very similar to that of cyanobacteria and to the PSII core complex of higher plants. In addition, the arrangement of the OEC proteins on the lumenal surface of the PSII complex is consistent to that obtained by X-ray crystallography of cyanobacterial PSII.

• MeSH
• bakteriální proteiny chemie   genetika   metabolismus   MeSH
• bílkoviny řas chemie   genetika   metabolismus   ultrastruktura   MeSH
• fotosystém II (proteinový komplex) chemie   genetika   metabolismus   ultrastruktura   MeSH
• kvarterní struktura proteinů * MeSH
• kyslík metabolismus   MeSH
• makromolekulární látky MeSH
• molekulární modely MeSH
• podjednotky proteinů chemie   genetika   metabolismus   MeSH
• Porphyridium chemie   cytologie   metabolismus   MeSH
• tylakoidy chemie   ultrastruktura   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• bílkoviny řas MeSH
• fotosystém II (proteinový komplex) MeSH
• kyslík MeSH
• makromolekulární látky MeSH
• podjednotky proteinů MeSH