4bth
From Proteopedia
The LeuA146Trp,PheB24Tyr Double Mutant of the Quorum Quenching N-acyl Homoserine Lactone Acylase PvdQ Has an Altered Substrate Specificity Towards Small Acyl Chains
Structural highlights
Function[PVDQ_PSEAE] Catalyzes the deacylation of acyl-homoserine lactone (AHL or acyl-HSL), releasing homoserine lactone (HSL) and the corresponding fatty acid. Possesses a specificity for the degradation of long-chain acyl-HSLs (side chains of 11 to 14 carbons in length). Degrades 3-oxo-C12-HSL, one of the two main AHL signal molecules of P.aeruginosa, and thereby functions as a quorum quencher, inhibiting the las quorum-sensing system. Therefore, may enable P.aeruginosa to modulate its own quorum-sensing-dependent pathogenic potential. Also appears to be required for pyoverdin biosynthesis.[1] [2] [3] Publication Abstract from PubMedThe use of enzymes to interfere with quorum sensing represents an attractive strategy to fight bacterial infections. We used PvdQ, an effective quorum-quenching enzyme from Pseudomonas aeruginosa, as a template to generate an acylase able to effectively hydrolyze C8-HSL, the major communication molecule produced by the Burkholderia species. We discovered that the combination of two single mutations leading to variant PvdQ(Lalpha146W,Fbeta24Y) conferred high activity toward C8-HSL. Exogenous addition of PvdQ(Lalpha146W,Fbeta24Y) dramatically decreased the amount of C8-HSL present in Burkholderia cenocepacia cultures and inhibited a quorum sensing-associated phenotype. The efficacy of this PvdQ variant to combat infections in vivo was further confirmed by its ability to rescue Galleria mellonella larvae upon infection, demonstrating its potential as an effective agent toward Burkholderia infections. Kinetic analysis of the enzymatic activities toward 3-oxo-C12-L-HSL and C8-L-HSL corroborated a substrate switch. This work demonstrates the effectiveness of quorum-quenching acylases as potential novel antimicrobial drugs. In addition, we demonstrate that their substrate range can be easily switched, thereby paving the way to selectively target only specific bacterial species inside a complex microbial community. Reducing virulence of the human pathogen Burkholderia by altering the substrate specificity of the quorum-quenching acylase PvdQ.,Koch G, Nadal-Jimenez P, Reis CR, Muntendam R, Bokhove M, Melillo E, Dijkstra BW, Cool RH, Quax WJ Proc Natl Acad Sci U S A. 2014 Jan 28;111(4):1568-73. doi:, 10.1073/pnas.1311263111. Epub 2014 Jan 13. PMID:24474783[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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