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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 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2004/04 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | The F subunit of Thermus thermophilus V-1-ATPase promotes ATPase activity but is not necessary for rotation |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF BIOLOGICAL CHEMISTRY |
| 出版社・発行元 | AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC |
| 巻・号・頁 | 279(17),pp.18085-18090 |
| 著者・共著者 | H Imamura,C Ikeda,M Yoshida,K Yokoyama |
| 概要 | V-1-ATPase from the thermophilic bacterium Thermus thermophilus is a molecular rotary motor with a subunit composition of A(3)B(3)DF, and its central rotor is composed of the D and F subunits. To determine the role of the F subunit, we generated an A(3)B(3)D subcomplex and compared it with A(3)B(3)DF. The ATP hydrolyzing activity of A(3)B(3)D (V-max = 20 s(-1)) was lower than that of A(3)B(3)DF (V-max = 31 s(-1)) and was more susceptible to MgADP inhibition during ATP hydrolysis. A3B3D was able to bind the F subunit to form A(3)B(3)DF. The C-terminally truncated F(Delta85-106) subunit was also bound to A(3)B(3)D, but the F(Delta69-106) subunit was not, indicating the importance of residues 69 - 84 of the F subunit for association with A(3)B(3)D. The ATPase activity of A(3)B(3)DF((Delta85-106)) (V-max = 24 s(-1)) was intermediate between that of A(3)B(3)D and A(3)B(3)DF. A single molecule experiment showed the rotation of the D subunit in A(3)B(3)D, implying that the F subunit is a dispensable component for rotation itself. Thus, the F subunit binds peripherally to the D subunit, but promotes V-1-ATPase catalysis. |
| DOI | 10.1074/jbc.M314204200 |
| ISSN | 0021-9258 |
| PMID | 14963028 |