4gd3

Structure of E. coli hydrogenase-1 in complex with cytochrome b

spinqualitylabelsall models 4gd3, resolution 3.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4gd3 is a 10 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.3Å Ligands: CL, FCO, HEM, LMT, MG, NI Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MBHS_ECOLI This is one of three E.coli hydrogenases synthesized in response to different physiological conditions. HYD1 is believed to have a role in hydrogen cycling during fermentative growth. Publication Abstract from PubMed We report the 3.3 A resolution structure of dimeric membrane-bound O(2)-tolerant hydrogenase 1 from Escherichia coli in a 2:1 complex with its physiological partner, cytochrome b. From the short distance between distal [Fe(4)S(4)] clusters, we predict rapid transfer of H(2)-derived electrons between hydrogenase heterodimers. Thus, under low O(2) levels, a functional active site in one heterodimer can reductively reactivate its O(2)-exposed counterpart in the other. Hydrogenase 1 is maximally expressed during fermentation, when electron acceptors are scarce. These conditions are achieved in the lower part of the host's intestinal tract when E. coli is soon to be excreted and undergo an anaerobic-to-aerobic metabolic transition. The apparent paradox of having an O(2)-tolerant hydrogenase expressed under anoxia makes sense if the enzyme functions to keep intracellular O(2) levels low by reducing it to water, protecting O(2)-sensitive enzymes during the transition. Cytochrome b's main role may be anchoring the hydrogenase to the membrane. Crystal Structure of the O(2)-Tolerant Membrane-Bound Hydrogenase 1 from Escherichia coli in Complex with Its Cognate Cytochrome b.,Volbeda A, Darnault C, Parkin A, Sargent F, Armstrong FA, Fontecilla-Camps JC Structure. 2012 Dec 19. pii: S0969-2126(12)00425-X. doi:, 10.1016/j.str.2012.11.010. PMID:23260654 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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