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Structure of the c14-rotor ring of the proton translocating chloroplast ATP synthase
Structural highlights
FunctionATPH_SPIOL 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 14 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 membrane integral rotor ring of the proton translocating F(1)F(0) ATP synthase from spinach chloroplasts was determined to 3.8 A resolution by x-ray crystallography. The rotor ring consists of 14 identical protomers that are symmetrically arranged around a central pore. Comparisons with the c(11) rotor ring of the sodium translocating ATPase from Ilyobacter tartaricus show that the conserved carboxylates involved in proton or sodium transport, respectively, are 10.6-10.8 A apart in both c ring rotors. This finding suggests that both ATPases have the same gear distance despite their different stoichiometries. The putative proton-binding site at the conserved carboxylate Glu(61) in the chloroplast ATP synthase differs from the sodium-binding site in Ilyobacter. Residues adjacent to the conserved carboxylate show increased hydrophobicity and reduced hydrogen bonding. The crystal structure reflects the protonated form of the chloroplast c ring rotor. We propose that upon deprotonation, the conformation of Glu(61) is changed to another rotamer and becomes fully exposed to the periphery of the ring. Reprotonation of Glu(61) by a conserved arginine in the adjacent a subunit returns the carboxylate to its initial conformation. Structure of the c14 rotor ring of the proton translocating chloroplast ATP synthase.,Vollmar M, Schlieper D, Winn M, Buchner C, Groth G J Biol Chem. 2009 Jul 3;284(27):18228-35. Epub 2009 May 7. PMID:19423706[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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