This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mori, H. Articles by Ito, K. Search for Related Content PubMed PubMed Citation Articles by Mori, H. Articles by Ito, K.

 Previous Article  |  Next Article 

Journal of Bacteriology, February 2003, p. 948-956, Vol. 185, No. 3
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.3.948-956.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

A SecE Mutation That Modulates SecY-SecE Translocase Assembly, Identified as a Specific Suppressor of SecY Defects

Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan

Received 30 September 2002/ Accepted 4 November 2002

The SecY39(Cs) (cold-sensitive) alteration of Arg357 results in a defect of translocation initiation. As a means to dissect the Sec translocation machinery, we isolated mutations that act as suppressors of the secY39 defect. A specific secE mutation, designated secE105, was thus isolated. This mutation proved to be identical with the prlG2 mutation and to suppress a number of cold-sensitive secY mutations. However, other prlG mutations did not effectively suppress the secY defects. Evidence indicates that the Ser105-to-Pro alteration in the C-terminal transmembrane segment of SecE weakens SecY-SecE association. In vitro analyses showed that the SecE(S105P) alteration preferentially stimulates the initial phase of translocation. It is suggested that the S105P alteration affects the SecYEG channel such that it is more prone to open and to accept the translocation initiation domain of a preprotein molecule.

This article has been cited by other articles:

• Mori, H., Ito, K. (2006). Different modes of SecY-SecA interactions revealed by site-directed in vivo photo-cross-linking. Proc. Natl. Acad. Sci. USA 103: 16159-16164 [Abstract] [Full Text]  
• Mori, H., Shimokawa, N., Satoh, Y., Ito, K. (2004). Mutational Analysis of Transmembrane Regions 3 and 4 of SecY, a Central Component of Protein Translocase. J. Bacteriol. 186: 3960-3969 [Abstract] [Full Text]