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The Bacillus subtilis signaling protein SpoIVB defines a new family of serine peptidases

Hoa, N T, Brannigan, J A and Cutting, S M (2002) The Bacillus subtilis signaling protein SpoIVB defines a new family of serine peptidases. Journal of Bacteriology. pp. 191-199. ISSN 0021-9193

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The protein SpoIVB plays a key role in signaling in the sigma (K) checkpoint of Bacillus subtilis. This regulatory mechanism coordinates late gene expression during development in this organism and we have recently shown SpoIVB to be a serine peptidase. SpoIVB signals by transiting a membrane, undergoing self-cleavage, and then by an unknown mechanism activating a zinc metalloprotease, SpoIVFB, which cleaves pro-sigma (K) to its active form, sigma (K), in the outer mother cell chamber of the developing cell. In this work we have characterized the serine peptidase domain of SpoIVB. Alignment of SpoIVB with homologues from other spore formers has allowed site-specific mutagenesis of all potential active site residues within the peptidase domain. We have defined the putative catalytic domain of the SpoIVB serine peptidase as a 160-amino-acid residue segment at the carboxyl terminus of the protein. His236 and Ser378 are the most important residues for proteolysis, with Asp363 being the most probable third member of the catalytic triad. In addition, we have shown that mutations at residues Asn290 and His394 lead to delayed signaling in the sigma (K) checkpoint. The active site residues suggest that SpoIVB and its homologues from other spore formers are members of a new family of serine peptidases of the trypsin superfamily.

Item Type: Article
Copyright, Publisher and Additional Information: Copyright © 2002 American Society for Microbiology
Institution: The University of York
Academic Units: The University of York > Chemistry (York)
Depositing User: Sherpa Assistant
Date Deposited: 04 Mar 2005
Last Modified: 13 Jul 2016 03:42
Published Version: http://dx.doi.org/10.1128/JB.184.1.191-199.2002
Status: Published
Refereed: Yes
URI: http://eprints.whiterose.ac.uk/id/eprint/313

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