HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 279, Issue 21, 22490-22497, May 21, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/21/22490    most recent M401008200v2 M401008200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vrontou, E. Articles by Economou, A. Search for Related Content PubMed PubMed Citation Articles by Vrontou, E. Articles by Economou, A. Social Bookmarking                      What's this?

Global Co-ordination of Protein Translocation by the SecA IRA1 Switch^*

Eleftheria Vrontou, Spyridoula Karamanou, Catherine Baud, Giorgos Sianidis, and Anastassios Economou

From the Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology and Department of Biology, University of Crete, P. O. Box 1527, GR-71110 Iraklio, Crete, Greece

SecA, the dimeric ATPase subunit of protein translocase, contains a DEAD helicase catalytic core that binds to a regulatory C-terminal domain. We now demonstrate that IRA1, a conserved helix-loop-helix structure in the C-domain, controls C-domain conformation through direct interdomain contacts. C-domain conformational changes are transmitted to the DEAD motor and alter its conformation. These interactions establish DEAD motor/C-domain conformational cross-talk that requires a functional IRA1. IRA1-controlled binding/release cycles of the C-domain to the DEAD motor couple this cross-talk to protein translocation chemistries, i.e. DEAD motor affinities for ligands (nucleotides, preprotein signal peptides, and SecYEG, the integral membrane component of translocase) and ATP turnover. IRA1-mediated global co-ordination of SecA catalysis is essential for protein translocation.

Received for publication, January 29, 2004 , and in revised form, March 4, 2004.

This paper is dedicated to the memory of Bob Macnab.

^* This work was supported by European Union Grants TMR-ERBFMRXCT960035, Biotech2-BIO4-CT98-0051, RTN1-1999-00149, QLK3-CT-2000-00082, and QLRT-2000-00122 and by a grant from Pfizer, Inc. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

To whom correspondence should be addressed. Tel./Fax: 30-2810-391166; E-mail: aeconomo{at}imbb.forth.gr.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				H. Mori and K. Ito The Long {alpha}-Helix of SecA Is Important for the ATPase Coupling of Translocation J. Biol. Chem., November 24, 2006; 281(47): 36249 - 36256. [Abstract] [Full Text] [PDF]

				E. Papanikou, S. Karamanou, C. Baud, M. Frank, G. Sianidis, D. Keramisanou, C. G. Kalodimos, A. Kuhn, and A. Economou Identification of the Preprotein Binding Domain of SecA J. Biol. Chem., December 30, 2005; 280(52): 43209 - 43217. [Abstract] [Full Text] [PDF]

				L. B. Jilaveanu, C. R. Zito, and D. Oliver Dimeric SecA is essential for protein translocation PNAS, May 24, 2005; 102(21): 7511 - 7516. [Abstract] [Full Text] [PDF]