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

J. Biol. Chem., Vol. 280, Issue 39, 33419-33425, September 30, 2005

This Article Full Text Full Text (PDF) An addition or correction has been published All Versions of this Article: 280/39/33419    most recent M504263200v1 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 Kennaway, C. K. Articles by Keep, N. H. Search for Related Content PubMed PubMed Citation Articles by Kennaway, C. K. Articles by Keep, N. H. Social Bookmarking                      What's this?

Dodecameric Structure of the Small Heat Shock Protein Acr1 from Mycobacterium tuberculosis^*

Christopher K. Kennaway, Justin L. P. Benesch, Ulrich Gohlke, Luchun Wang, Carol V. Robinson, Elena V. Orlova, Helen R. Saibi, and Nicholas H. Keep1

From the School of Crystallography and Institute of Structural Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX and the Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom

Small heat shock proteins are a ubiquitous and diverse family of stress proteins that have in common an -crystallin domain. Mycobacterium tuberculosis has two small heat shock proteins, Acr1 (-crystallin-related protein 1, or Hsp16.3/16-kDa antigen) and Acr2 (HrpA), both of which are highly expressed under different stress conditions. Small heat shock proteins form large oligomeric assemblies and are commonly polydisperse. Nanoelectrospray mass spectrometry showed that Acr2 formed a range of oligomers composed of dimers and tetramers, whereas Acr1 was a dodecamer. Electron microscopy of Acr2 showed a variety of particle sizes. Using three-dimensional analysis of negative stain electron microscope images, we have shown that Acr1 forms a tetrahedral assembly with 12 polypeptide chains. The atomic structure of a related -crystallin domain dimer was docked into the density to build a molecular structure of the dodecameric Acr1 complex. Along with the differential regulation of these two proteins, the differences in their quaternary structures demonstrated here supports their distinct functional roles.

Received for publication, April 19, 2005 , and in revised form, July 26, 2005.

The atomic coordinates and structure factors (code 2BYU) have been deposited in the Protein Data Bank, Research Collaboratory for Structural Bioinformatics, Rutgers University, New Brunswick, NJ (http://www.rcsb.org/).

^* This work was supported by a Medical Research Council UK studentship (to C. K. K.) and a component of European Union Grant QLK2-CT-2001-02018 (to N. H. K.). 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.

¹ To whom correspondence should be addressed. Tel.: 020-7631-6852; Fax: 020-7631-6803; E-mail: n.keep{at}mail.cryst.bbk.ac.uk.

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

This article has been cited by other articles:

				V. H. Hayes, G. Devlin, and R. A. Quinlan Truncation of {alpha}B-Crystallin by the Myopathy-causing Q151X Mutation Significantly Destabilizes the Protein Leading to Aggregate Formation in Transfected Cells J. Biol. Chem., April 18, 2008; 283(16): 10500 - 10512. [Abstract] [Full Text] [PDF]

				M. Ventura, C. Canchaya, Z. Zhang, G. F. Fitzgerald, and D. van Sinderen Molecular Characterization of hsp20, Encoding a Small Heat Shock Protein of Bifidobacterium breve UCC2003 Appl. Envir. Microbiol., July 15, 2007; 73(14): 4695 - 4703. [Abstract] [Full Text] [PDF]