Escherichia coli SecA shape and dimensions

被引：41

作者：

Shilton, B

Svergun, DI

Volkov, VV

Koch, MHJ

Cusack, S

Economou, A

机构：

[1] Univ Crete, Inst Mol Biol & Biotechnol, GR-71110 Iraklion, Crete, Greece

[2] Univ Crete, Dept Biol, GR-71110 Iraklion, Crete, Greece

[3] European Mol Biol Lab, D-22603 Hamburg, Germany

[4] Russian Acad Sci, Inst Crystallog, Moscow 117333, Russia

[5] European Mol Biol Lab, Grenoble Outstn, ILL, F-38042 Grenoble 9, France

来源：

FEBS LETTERS | 1998年 / 436卷 / 02期

关键词：

SecA; translocase; small angle X-ray scattering; SecYEG; preprotein translocation;

D O I：

10.1016/S0014-5793(98)01141-7

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

SecA shape and conformational flexibility in solution were studied by small angle X-ray scattering, Dimeric SecA is a very elongated molecule, 15 nm long and 8 nm wide. SecA is therefore four times as long as the membrane is wide. The two globular protomers are distinctly separated and share limited surface of intermolecular contacts. ATP, ADP or adenylyl-imidodiphosphate (AMP-PNP) binding does not alter the SecA radius of gyration. A SecA mutant that catalyzes multiple rounds of ATP hydrolysis does not undergo conformational changes detectable by small angle X-ray scattering (SAXS). We conclude that SecA conformational alterations observed biochemically during nucleotide interaction are only small-scale and localized. The ramifications of these findings on SecA/SecYEG interaction are discussed. (C) 1998 Federation of European Biochemical Societies.

引用

页码：277 / 282

页数：6

共 46 条

[1] SECA, AN ESSENTIAL COMPONENT OF THE SECRETORY MACHINERY OF ESCHERICHIA-COLI, EXISTS AS HOMODIMER [J].