ヨコヤマ ケン   YOKOYAMA KEN
  横山 謙
   所属   京都産業大学  生命科学部 先端生命科学科
   職種   教授
言語種別 英語
発行・発表の年月 2007/12
形態種別 研究論文
査読 査読あり
標題 Dodecamer rotor ring defines H+/ATP ratio for ATP synthesis of prokaryotic V-ATPase from Thermus thermophilus
執筆形態 その他
掲載誌名 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
出版社・発行元 NATL ACAD SCIENCES
巻・号・頁 104(51),pp.20256-20261
著者・共著者 Masashi Toei,Christoph Gerle,Masahiro Nakano,Kazutoshi Tani,Nobuhiko Gyobu,Masatada Tamakoshi,Nobuhito Sone,Masasuke Yoshida,Yoshinori Fujiyoshi,Kaoru Mitsuoka,Ken Yokoyama
概要 ATP synthesis by V-ATPase from the thermophilic bacterium Thermus thermophilus driven by the acid-base transition was investigated. The rate of ATP synthesis increased in parallel with the increase in proton motive force (PMF) >110 mV which is composed of a difference in proton concentration (Delta pH) and the electrical potential differences (Delta Psi) across membranes. The optimum rate of synthesis reached 85 s(-1), and the H+/ATP ratio of 4.0 +/- 0.1 was obtained. ATP was synthesized at a considerable rate solely by Delta pH, indicating Delta Psi was not absolutely required for synthesis. Consistent with the H+/ATP ratio, cryoelectron micrograph images of 2D crystals of the membrane-bound rotor ring of the V-ATPase at 7.0-angstrom resolution showed the presence of 12 V-o-c subunits, each composed of two transmembrane helices. These results indicate that symmetry mismatch between the rotor and catalytic domains is not obligatory for rotary ATPases/synthases.
DOI 10.1073/pnas.0706914105
ISSN 0027-8424
PMID 18077374