In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 108, No. 29 ( 2011-07-19), p. 12089-12094
Abstract:
Quorum sensing (QS) controls certain behaviors of bacteria in response to population density. In Gram-negative bacteria, QS is often mediated by N -acyl- l -homoserine lactones (acyl-HSLs). Because QS influences the virulence of many pathogenic bacteria, synthetic inhibitors of acyl-HSL synthases might be useful therapeutically for controlling pathogens. However, rational design of a potent QS antagonist has been thwarted by the lack of information concerning the binding interactions between acyl-HSL synthases and their ligands. In the Gram-negative bacterium Burkholderia glumae , QS controls virulence, motility, and protein secretion and is mediated by the binding of N -octanoyl- l -HSL (C8-HSL) to its cognate receptor, TofR. C8-HSL is synthesized by the acyl-HSL synthase TofI. In this study, we characterized two previously unknown QS inhibitors identified in a focused library of acyl-HSL analogs. Our functional and X-ray crystal structure analyses show that the first inhibitor, J8-C8, binds to TofI, occupying the binding site for the acyl chain of the TofI cognate substrate, acylated acyl-carrier protein. Moreover, the reaction byproduct, 5′-methylthioadenosine, independently binds to the binding site for a second substrate, S -adenosyl- l -methionine. Closer inspection of the mode of J8-C8 binding to TofI provides a likely molecular basis for the various substrate specificities of acyl-HSL synthases. The second inhibitor, E9C-3oxoC6, competitively inhibits C8-HSL binding to TofR. Our analysis of the binding of an inhibitor and a reaction byproduct to an acyl-HSL synthase may facilitate the design of a new class of QS-inhibiting therapeutic agents.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1103165108
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2011
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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