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

J. Biol. Chem., Vol. 281, Issue 46, 35467-35477, November 17, 2006

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 281/46/35467    most recent M607047200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lewin, A. Articles by Le Brun, N. E. Search for Related Content PubMed PubMed Citation Articles by Lewin, A. Articles by Le Brun, N. E. Social Bookmarking                      What's this?

Molecular Basis for Specificity of the Extracytoplasmic Thioredoxin ResA^*

Allison Lewin, Allister Crow, Arthur Oubrie¹, and Nick E. Le Brun²

From the School of Chemical Sciences and Pharmacy and School of Biological Sciences, Centre for Metalloprotein Spectroscopy and Biology, University of East Anglia, Norwich NR4 7TJ, United Kingdom

ResA, an extracytoplasmic thioredoxin from Bacillus subtilis, acts in cytochrome c maturation by reducing the disulfide bond present in apocytochromes prior to covalent attachment of heme. This reaction is (and has to be) specific, as broad substrate specificity would result in unproductive shortcircuiting with the general oxidizing thioredoxin(s) present in the same compartment. Using mutational analysis and subsequent biochemical and structural characterization of active site variants, we show that reduced ResA displays unusually low reactivity at neutral pH, consistent with the observed high pK_a values >8 for both active site cysteines. Residue Glu⁸⁰ is shown to play a key role in controlling the acid-base properties of the active site. A model in which substrate binding dramatically enhances the reactivity of the active site cysteines is proposed to account for the specificity of the protein. Such a substratemediated activation mechanism is likely to have wide relevance for extracytoplasmic thioredoxins.

Received for publication, July 25, 2006 , and in revised form, August 31, 2006.

The atomic coordinates and structure factors (codes 2H1A, 2H19, 2H1G, 2H1B, and 2H1D) 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 in part by BBSRC Grant BB/C503597/1 and the Wellcome Trust Grant 076017/Z/04/Z. 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.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1-S5 and Equations S1-S24.

¹ Present address: Organon N.V., Dept. of Molecular Design and Informatics, Molenstraat 110, 5342 CC Oss, The Netherlands.

² To whom correspondence should be addressed: School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, NR4 7TJ, UK. Tel.: 44-1603-592699; Fax: 44-1603-592003; E-mail: n.le-brun{at}uea.ac.uk.

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

This article has been cited by other articles:

				A. Crow, Y. Liu, M. C. Moller, N. E. Le Brun, and L. Hederstedt Structure and Functional Properties of Bacillus subtilis Endospore Biogenesis Factor StoA J. Biol. Chem., April 10, 2009; 284(15): 10056 - 10066. [Abstract] [Full Text] [PDF]

				P. R. Race, M. L. Bentley, J. A. Melvin, A. Crow, R. K. Hughes, W. D. Smith, R. B. Sessions, M. A. Kehoe, D. G. McCafferty, and M. J. Banfield Crystal Structure of Streptococcus pyogenes Sortase A: IMPLICATIONS FOR SORTASE MECHANISM J. Biol. Chem., March 13, 2009; 284(11): 6924 - 6933. [Abstract] [Full Text] [PDF]

				C. T. C. Hodson, A. Lewin, L. Hederstedt, and N. E. Le Brun The Active-Site Cysteinyls and Hydrophobic Cavity Residues of ResA Are Important for Cytochrome c Maturation in Bacillus subtilis J. Bacteriol., July 1, 2008; 190(13): 4697 - 4705. [Abstract] [Full Text] [PDF]

				B. Heras, M. Kurz, R. Jarrott, S. R. Shouldice, P. Frei, G. Robin, M. Cemazar, L. Thony-Meyer, R. Glockshuber, and J. L. Martin Staphylococcus aureus DsbA Does Not Have a Destabilizing Disulfide: A NEW PARADIGM FOR BACTERIAL OXIDATIVE FOLDING J. Biol. Chem., February 15, 2008; 283(7): 4261 - 4271. [Abstract] [Full Text] [PDF]

				A. Di Matteo, S. Gianni, M. E. Schinina, A. Giorgi, F. Altieri, N. Calosci, M. Brunori, and C. Travaglini-Allocatelli A Strategic Protein in Cytochrome c Maturation: THREE-DIMENSIONAL STRUCTURE OF CcmH AND BINDING TO APOCYTOCHROME c J. Biol. Chem., September 14, 2007; 282(37): 27012 - 27019. [Abstract] [Full Text] [PDF]