3l91
Structure of Pseudomonas aerugionsa PvdQ bound to octanoate
Structural highlights
FunctionPVDQ_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 human pathogen Pseudomonas aeruginosa produces a variety of virulence factors including pyoverdine, a nonribosomally produced peptide siderophore. The maturation pathway of the pyoverdine peptide is complex and provides a unique target for inhibition. Within the pyoverdine biosynthetic cluster is a periplasmic hydrolase, PvdQ, that is required for pyoverdine production. However, the precise role of PvdQ in the maturation pathway has not been biochemically characterized. We demonstrate herein that the initial module of the nonribosomal peptide synthetase PvdL adds a myristate moiety to the pyoverdine precursor. We extracted this acylated precursor, called PVDIq, from a pvdQ mutant strain and show that the PvdQ enzyme removes the fatty acid catalyzing one of the final steps in pyoverdine maturation. Incubation of PVDIq with crystals of PvdQ allowed us to capture the acylated enzyme and confirm through structural studies the chemical composition of the incorporated acyl chain. Finally, because inhibition of siderophore synthesis has been identified as a potential antibiotic strategy, we developed a high-throughput screening assay and tested a small chemical library for compounds that inhibit PvdQ activity. Two compounds that block PvdQ have been identified, and their binding within the fatty acid binding pocket was structurally characterized. Structural Characterization and High-Throughput Screening of Inhibitors of PvdQ, an NTN Hydrolase Involved in Pyoverdine Synthesis.,Drake EJ, Gulick AM ACS Chem Biol. 2011 Sep 15. PMID:21892836[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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