4ogq
Internal Lipid Architecture of the Hetero-Oligomeric Cytochrome b6f ComplexInternal Lipid Architecture of the Hetero-Oligomeric Cytochrome b6f Complex
Structural highlights
FunctionCYB6_NOSS1 Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions (By similarity). Publication Abstract from PubMedThe role of lipids in the assembly, structure, and function of hetero-oligomeric membrane protein complexes is poorly understood. The dimeric photosynthetic cytochrome b6f complex, a 16-mer of eight distinct subunits and 26 transmembrane helices, catalyzes transmembrane proton-coupled electron transfer for energy storage. Using a 2.5 A crystal structure of the dimeric complex, we identified 23 distinct lipid-binding sites per monomer. Annular lipids are proposed to provide a connection for super-complex formation with the photosystem-I reaction center and the LHCII kinase enzyme for transmembrane signaling. Internal lipids mediate crosslinking to stabilize the domain-swapped iron-sulfur protein subunit, dielectric heterogeneity within intermonomer and intramonomer electron transfer pathways, and dimer stabilization through lipid-mediated intermonomer interactions. This study provides a complete structure analysis of lipid-mediated functions in a multi-subunit membrane protein complex and reveals lipid sites at positions essential for assembly and function. Internal Lipid Architecture of the Hetero-Oligomeric Cytochrome b6f Complex.,Hasan SS, Cramer WA Structure. 2014 Jul 8;22(7):1008-15. doi: 10.1016/j.str.2014.05.004. Epub 2014, Jun 12. PMID:24931468[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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