1a91
SUBUNIT C OF THE F1FO ATP SYNTHASE OF ESCHERICHIA COLI; NMR, 10 STRUCTURES
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 PubMedSubunit c is the H+-translocating component of the F1F0 ATP synthase complex. H+ transport is coupled to conformational changes that ultimately lead to ATP synthesis by the enzyme. The properties of the monomeric subunit in a single-phase solution of chloroform-methanol-water (4:4:1) have been shown to mimic those of the protein in the native complex. Triple resonance NMR experiments were used to determine the complete structure of monomeric subunit c in this solvent mixture. The structure of the protein was defined by >2000 interproton distances, 64 (3)JN alpha, and 43 hydrogen-bonding NMR-derived restraints. The root mean squared deviation for the backbone atoms of the two transmembrane helices was 0.63 A. The protein folds as a hairpin of two antiparallel helical segments, connected by a short structured loop. The conserved Arg41-Gln42-Pro43 form the top of this loop. The essential H+-transporting Asp61 residue is located at a slight break in the middle of the C-terminal helix, just prior to Pro64. The C-terminal helix changes direction by 30 +/- 5 degrees at the conserved Pro64. In its protonated form, the Asp61 lies in a cavity created by the absence of side chains at Gly23 and Gly27 in the N-terminal helix. The shape and charge distribution of the molecular surface of the monomeric protein suggest a packing arrangement for the oligomeric protein in the F0 complex, with the front face of one monomer packing favorably against the back face of a second monomer. The packing suggests that the proton (cation) binding site lies between packed pairs of adjacent subunit c. Solution structure of the transmembrane H+-transporting subunit c of the F1F0 ATP synthase.,Girvin ME, Rastogi VK, Abildgaard F, Markley JL, Fillingame RH Biochemistry. 1998 Jun 23;37(25):8817-24. PMID:9636021[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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