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

This Article Full Text Full Text (PDF) 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 CrossRef Citing Articles via Google Scholar Google Scholar Articles by Zurawski, D. V. Articles by Stein, M. A. Search for Related Content PubMed PubMed Citation Articles by Zurawski, D. V. Articles by Stein, M. A. Agricola Articles by Zurawski, D. V. Articles by Stein, M. A.

The SPI2-encoded SseA chaperone has discrete domains required for SseB stabilization and export, and binds within the C-terminus of SseB and SseD

Department of Microbiology and Molecular Genetics and the Department of Animal Sciences, Markey Center for Molecular Genetics, University of Vermont, 95 Carrigan Drive, Room 118, Stafford Hall, Burlington, VT 05405, USA

Correspondence
Murry A. Stein
mastein{at}uvm.edu

SseA, a key Salmonella virulence determinant, is a small, basic pI protein encoded within the Salmonella pathogenicity island 2 and serves as a type III secretion system chaperone for SseB and SseD. Both SseA partners are subunits of the surface-localized translocon module that delivers effectors into the host cell; SseB is predicted to compose the translocon sheath and SseD is a putative translocon pore subunit. In this study, SseA molecular interactions with its partners were characterized further. Yeast two-hybrid screens indicate that SseA binding requires a C-terminal domain within both partners. An additional central domain within SseD was found to influence binding. The SseA-binding region within SseB was found to encompass a predicted amphipathic helix of a type participating in coiled-coil interactions that are implicated in the assembly of translocon sheaths. Deletions that impinge upon this putative coiled-coiled domain prevent SseA binding, suggesting that SseA occupies a portion of the coiled-coil. SseA occupancy of this motif is envisioned to be sufficient to prevent premature SseB self-association inside bacteria. Domain mapping on the chaperone was also performed. A deletion of the SseA N-terminus, or site-directed mutations within this region, allowed stabilization of SseB, but its export was disrupted. Therefore, the N-terminus of SseA provides a function that is essential for SseB export, but dispensable for partner binding and stabilization.

This article has been cited by other articles:

				J. Zheng, N. Li, Y. P. Tan, J. Sivaraman, Y.-K. Mok, Z. L. Mo, and K. Y. Leung EscC is a chaperone for the Edwardsiella tarda type III secretion system putative translocon components EseB and EseD Microbiology, June 1, 2007; 153(6): 1953 - 1962. [Abstract] [Full Text] [PDF]