7p91

TmHydABC- T. maritima bifurcating hydrogenase with bridge domain closed

spinqualitylabelsall models 7p91, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7p91 is a 6 chain structure with sequence from Thermotoga maritima MSB8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FES, FMN, SF4, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [G4FFG0_THEMA] Publication Abstract from PubMed Electron-bifurcation is a fundamental energy conservation mechanism in nature in which two electrons from an intermediate potential electron donor are split so that one is sent along a high potential pathway to a high potential acceptor and the other is sent along a low potential pathway to a low potential acceptor. This process allows endergonic reactions to be driven by exergonic ones and is an alternative, less recognised, mechanism of energy coupling to the well-known chemiosmotic principle. The electron-bifurcating [FeFe] hydrogenase from Thermotoga maritima (HydABC) requires both NADH and ferredoxin to reduce protons generating hydrogen. The mechanism of electron-bifurcation in HydABC remains enigmatic in spite of intense research efforts over the last few years. Structural information may provide the basis for a better understanding of spectroscopic and functional information. Here, we present a 2.3 A electron cryo-microscopy structure of HydABC. The structure shows a heterododecamer composed of two independent 'halves' each made of two strongly interacting HydABC heterotrimers connected via a [4Fe-4S] cluster. A central electron transfer pathway connects the active sites for NADH oxidation and for proton reduction. We identified two conformations of a flexible iron-sulfur cluster domain: a 'closed bridge' and an 'open bridge' conformation, where a Zn(2+) site may act as a 'hinge' allowing domain movement. Based on these structural revelations, we propose a possible mechanism of electron-bifurcation in HydABC where the flavin mononucleotide serves a dual role as both the electron bifurcation center and as the NAD(+) reduction/NADH oxidation site. Structural insight on the mechanism of an electron-bifurcating [FeFe] hydrogenase.,Furlan C, Chongdar N, Gupta P, Lubitz W, Ogata H, Blaza JN, Birrell JA Elife. 2022 Aug 26;11. pii: 79361. doi: 10.7554/eLife.79361. PMID:36018003 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA