Download MendeleyInternal Lipid Architecture of the Hetero-Oligomeric Cytochrome b6f Complex.
Hasan, S.S., Cramer, W.A.(2014) Structure 22: 1008-1015
- PubMed: 24931468
- DOI: https://doi.org/10.1016/j.str.2014.05.004
- Primary Citation of Related Structures:
4OGQ - PubMed Abstract:
The 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 Å 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.
Organizational Affiliation:
Department of Biological Sciences, Hockmeyer Hall of Structural Biology, Purdue University, West Lafayette, IN 47907, USA. Electronic address: [email protected].
