5y82 | pdb_00005y82
Crystal structure of the periplasmic domain of the Thermotoga maritima YidC
Structural highlights
Function[YIDC_THEMA] Required for the insertion and/or proper folding and/or complex formation of integral membrane proteins into the membrane. Involved in integration of membrane proteins that insert both dependently and independently of the Sec translocase complex, as well as at least some lipoproteins. Aids folding of multispanning membrane proteins. Publication Abstract from PubMedThe evolutionarily conserved YidC/Oxa1/Alb3 family of proteins represents a unique membrane protein family that facilitates the insertion, folding, and assembly of a cohort of alpha-helical membrane proteins in all kingdoms of life, yet its underlying mechanisms remain elusive. We report the crystal structures of the full-length Thermotoga maritima YidC (TmYidC) and the TmYidC periplasmic domain (TmPD) at a resolution of 3.8 and 2.5 A, respectively. The crystal structure of TmPD reveals a beta-supersandwich fold but with apparently shortened beta strands and different connectivity, as compared to the Escherichia coli YidC (EcYidC) periplasmic domain (EcPD). TmYidC in a detergent-solubilized state also adopts a monomeric form and its conserved core domain, which consists of 2 loosely associated alpha-helical bundles, assemble a fold similar to that of the other YidC homologues, yet distinct from that of the archaeal YidC-like DUF106 protein. Functional analysis using in vivo photo-crosslinking experiments demonstrates that Pf3 coat protein, a Sec-independent YidC substrate, exits to the lipid bilayer laterally via one of the 2 alpha-helical bundle interfaces: TM3-TM5. Engineered intramolecular disulfide bonds in TmYidC, in combination with complementation assays, suggest that significant rearrangement of the 2 alpha-helical bundles at the top of the hydrophilic groove is critical for TmYidC function. These experiments provide a more detailed mechanical insight into YidC-mediated membrane protein biogenesis.-Xin, Y., Zhao, Y., Zheng, J., Zhou, H., Zhang, X. C., Tian, C., Huang, Y. Structure of YidC from Thermotoga maritima and its implications for YidC-mediated membrane protein insertion. Structure of YidC from Thermotoga maritima and its implications for YidC-mediated membrane protein insertion.,Xin Y, Zhao Y, Zheng J, Zhou H, Zhang XC, Tian C, Huang Y FASEB J. 2018 May;32(5):2411-2421. doi: 10.1096/fj.201700893RR. Epub 2018 Jan 2. PMID:29295859[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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