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Solution Structure of Ala20Pro/Pro64Ala substituted subunit c of Escherichia coli ATP synthase
Structural highlights
FunctionATPL_ECOLI F(1)F(0) ATP synthase produces ATP from ADP in the presence of a proton or sodium gradient. F-type ATPases consist of two structural domains, F(1) containing the extramembraneous catalytic core and F(0) containing the membrane proton channel, linked together by a central stalk and a peripheral stalk. During catalysis, ATP synthesis in the catalytic domain of F(1) is coupled via a rotary mechanism of the central stalk subunits to proton translocation.[HAMAP-Rule:MF_01396] Key component of the F(0) channel; it plays a direct role in translocation across the membrane. A homomeric c-ring of 10 subunits forms the central stalk rotor element with the F(1) delta and epsilon subunits.[HAMAP-Rule:MF_01396] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe structure of the A20P/P64A mutated subunit c of Escherichia coli ATP synthase, in which the essential proline has been switched from residue 64 of the second transmembrane helix (TMH) to residue 20 of the first TMH, has been solved by (15)N,(1)H NMR in a monophasic chloroform/methanol/water (4:4:1) solvent mixture. The cA20P/P64A mutant grows as well as wild type, and the F(0)F(1) complex is fully functional in ATPase-coupled H(+) pumping. Residues 20 and 64 lie directly opposite to each other in the hairpin-like structure of wild type subunit c, and the prolinyl 64 residue is thought to induce a slight bend in TMH-2 such that it wraps around a more straightened TMH-1. In solution, the A20P/P64A substituted subunit c also forms a hairpin of two alpha-helices, with residues 41-45 forming a connecting loop as in the case of the wild type protein, but, in this case, Pro(20) induces a bend in TMH-1, which then packs against a more straightened TMH-2. The essential prolinyl residue, whether at position 64 or 20, lies close to the aspartyl 61 H(+) binding site. The prolinyl residue may introduce structural flexibility in this region of the protein, which may be necessary for the proposed movement of the alpha-helical segments during the course of the H(+) pumping catalytic cycle. Structure of Ala(20) --> Pro/Pro(64) --> Ala substituted subunit c of Escherichia coli ATP synthase in which the essential proline is switched between transmembrane helices.,Dmitriev OY, Fillingame RH J Biol Chem. 2001 Jul 20;276(29):27449-54. Epub 2001 Apr 30. PMID:11331283[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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