5m5h
RIBOSOME-BOUND YIDC INSERTASERIBOSOME-BOUND YIDC INSERTASE
Structural highlights
FunctionYIDC_ECOLI Inner membrane protein required for the insertion and/or proper folding and/or complex formation of integral inner membrane proteins. Involved in integration of membrane proteins that insert dependently and independently of the Sec translocase complex, as well as at least 2 lipoproteins. Its own insertion requires SRP and is Sec translocase-dependent. Essential for the integration of Sec-dependent subunit a of the F(0)ATP synthase, FtsQ and SecE proteins and for Sec-independent subunit c of the F(0)ATP synthase, M13 phage procoat and the N-terminus of leader peptidase Lep. Probably interacts directly with Sec-independent substrates. Sec-dependent protein FtsQ interacts first with SecY then subsequently with YidC. Sec-dependent LacY and MalF require YidC to acquire tertiary structure and stability, a chaperone-like function, but not for membrane insertion. Stable maltose transport copmplex formation (MalFGK(2)) also requires YidC. Partially complements a Streptococcus mutans yidC2 disruption mutant.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedMembers of the YidC/Oxa1/Alb3 family universally facilitate membrane protein biogenesis, via mechanisms that have thus far remained unclear. Here, we investigated two crucial functional aspects: the interaction of YidC with ribosome:nascent chain complexes (RNCs) and the structural dynamics of RNC-bound YidC in nanodiscs. We observed that a fully exposed nascent transmembrane domain (TMD) is required for high-affinity YidC:RNC interactions, while weaker binding may already occur at earlier stages of translation. YidC efficiently catalyzed the membrane insertion of nascent TMDs in both fluid and gel phase membranes. Cryo-electron microscopy and fluorescence analysis revealed a conformational change in YidC upon nascent chain insertion: the essential TMDs 2 and 3 of YidC were tilted, while the amphipathic helix EH1 relocated into the hydrophobic core of the membrane. We suggest that EH1 serves as a mechanical lever, facilitating a coordinated movement of YidC TMDs to trigger the release of nascent chains into the membrane. Structural Dynamics of the YidC:Ribosome Complex during Membrane Protein Biogenesis.,Kedrov A, Wickles S, Crevenna AH, van der Sluis EO, Buschauer R, Berninghausen O, Lamb DC, Beckmann R Cell Rep. 2016 Dec 13;17(11):2943-2954. doi: 10.1016/j.celrep.2016.11.059. PMID:27974208[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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