4GD3

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

Summary for 4GD3

• Entry DOI: 10.2210/pdb4gd3/pdb
• Related: 3UQY 3USC 3USE
• Descriptor: Hydrogenase-1 small chain, DODECYL-BETA-D-MALTOSIDE, PROTOPORPHYRIN IX CONTAINING FE, ... (12 entities in total)
• Functional Keywords: o2-tolerant h2:quinone oxidoreductase, membrane-bound, ni-fe-hydrogenase-cytochrome b complex, oxidoreductase-electron transport complex, oxidoreductase/electron transport
• Biological source: Escherichia coli; More
• Cellular location: Cell inner membrane; Single-pass type I membrane protein; Periplasmic side: P69739; Cell membrane; Peripheral membrane protein: P0ACD8; Cell inner membrane; Multi-pass membrane protein: P0AAM1
• Total number of polymer chains: 10
• Total formula weight: 470137.85

Authors

Volbeda, A.,Fontecilla-Camps, J.C.,Darnault, C. (deposition date: 2012-07-31, release date: 2013-01-02, Last modification date: 2023-09-13)

Primary citation

Volbeda, A.,Darnault, C.,Parkin, A.,Sargent, F.,Armstrong, F.A.,Fontecilla-Camps, J.C.
Crystal Structure of the O(2)-Tolerant Membrane-Bound Hydrogenase 1 from Escherichia coli in Complex with Its Cognate Cytochrome b.
Structure, 21:184-190, 2013

PubMed Abstract: We report the 3.3 Å 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.

PubMed: 23260654
DOI: 10.1016/j.str.2012.11.010

Experimental method

X-RAY DIFFRACTION (3.3 Å)