期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：39
页码：16823-16827
DOI：10.1073/pnas.1011099107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The catalytic domain of the F-ATPase in mitochondria protrudes into the matrix of the organelle, and is attached to the membrane domain by central and peripheral stalks. Energy for the synthesis of ATP from ADP and phosphate is provided by the transmembrane proton-motive-force across the inner membrane, generated by respiration. The proton-motive force is coupled mechanically to ATP synthesis by the rotation at about 100 times per second of the central stalk and an attached ring of c-subunits in the membrane domain. Each c-subunit carries a glutamate exposed around the midpoint of the membrane on the external surface of the ring. The rotation is generated by protonation and deprotonation successively of each glutamate. Each 360{degrees} rotation produces three ATP molecules, and requires the translocation of one proton per glutamate by each c-subunit in the ring. In fungi, eubacteria, and plant chloroplasts, ring sizes of c10-c15 subunits have been observed, implying that these enzymes need 3.3-5 protons to make each ATP, but until now no higher eukaryote has been examined. As shown here in the structure of the bovine F1-c-ring complex, the c-ring has eight c-subunits. As the sequences of c-subunits are identical throughout almost all vertebrates and are highly conserved in invertebrates, their F-ATPases probably contain c8-rings also. Therefore, in about 50,000 vertebrate species, and probably in many or all of the two million invertebrate species, 2.7 protons are required by the F-ATPase to make each ATP molecule.
关键词：ATP synthase ; rotational catalysis ; c-ring structure ; protons per ATP ; vertebrates
