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A novel extracellular phospholipase C of Pseudomonas aeruginosa is required for phospholipid chemotaxis
Author(s) -
Barker Adam P.,
Vasil Adriana I.,
Filloux Alain,
Ball Genevieve,
Wilderman Paula J.,
Vasil Michael L.
Publication year - 2004
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2004.04189.x
Subject(s) - biology , chemotaxis , pseudomonas aeruginosa , extracellular , phospholipid , microbiology and biotechnology , phospholipase , phospholipase c , phospholipase d , pseudomonadales , biochemistry , bacteria , enzyme , genetics , membrane , receptor
Summary Pseudomonas aeruginosa and other bacterial pathogens express one or more homologous extracellular phospholipases C (PLC) that are secreted through the inner membrane via the twin arginine translocase (TAT) pathway. Analysis of TAT mutants of P. aeruginosa uncovered a previously unidentified extracellular PLC that is secreted via the Sec pathway (PlcB). Whereas all presently known PLCs of P. aeruginosa (PlcH, PlcN and PlcB) hydrolyse phosphatidylcholine (PC), only PlcB is active on phosphatidylethanolamine (PE). plcB candidates were identified based on deductions made from bioinformatics data and extant DNA microarray data. Among these candidates, a gene (PA0026) required for the expression of an extracellular PE‐PLC was identified. The protein encoded by PA0026 has limited, but significant similarity, over a short region (∼60aa of 328), to a class of zinc‐dependent prokaryotic PLCs. A conserved His residue of PlcB (His216) that is required for coordinate binding of zinc in this class of PLCs was mutated. Analysis of this mutant established that the protein encoded by PA0026 is PlcB. Three in‐dependent recently published reports indicate that homoserine lactone‐mediated quorum sensing regulates the expression of PA0026 (i.e. plcB ). PlcB, but not PlcH or PlcN, is required for directed twitching motility up a gradient of certain kinds of phospholipids. This response shows specificity for the fatty acid moiety of the phospholipid.