Depletion of SecDF‐YajC causes a decrease in the level of SecG: implication for their functional interaction

FEBS Letters

Nishiyama, Ken-ichi¹  Kato, Yoshihisa¹  Tokuda, Hajime¹ 

[1]Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan

关键词: Protein translocation;    Sec machinery;    SecDF-YajC;    SecG;    Inverted membrane vesicle;    CCCP;    carbonyl cyanide m-chlorophenylhydrazone;    proOmpA;    precursor of outer membrane protein A (OmpA);    OD;    optical density;    NEM;    N-ethylmaleimide;    IPTG;    isopropyl β-D-thiogalactopyranoside;    IMV;    inverted membrane vesicle;   

DOI  :  10.1016/S0014-5793(03)00847-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

SecA and an apparatus comprising SecYEG and SecDF-YajC complexes catalyze protein translocation across the Escherichia coli membrane. SecDF-YajC and SecG facilitate membrane insertion of SecA, which is the driving force for protein translocation. Here we report that SecDF-YajC depletion together with SecG depletion nearly completely inhibits protein translocation both in vivo and in vitro, although SecDF-YajC had been thought to be unnecessary for in vitro translocation. The level of SecG in membranes decreased to about half upon SecDF-YajC depletion and recovered to a normal level when SecDF-YajC was expressed. SecDF-YajC inhibited disulfide bond formation between two SecG molecules possessing a single cysteine residue. These results suggest functional interaction between SecDF-YajC and SecG.

【 授权许可】

Unknown