Cloning and characterization of a nonhemolytic phospholipase C gene from Burkholderia pseudomallei

We cloned and characterized a phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC) gene from Burkholderia pseudomallei, DNA sequence analysis of t he gene indicated an open reading frame coding for 700 amino acids with a 3 4-amino-acid signal peptide. When cleaved, this yields a secreted 73-kDa ma ture protein. The deduced amino acid sequence exhibited 48% similarity to t hat of a nonhemolytic PLC from Pseudomonas aeruginosa, The expressed PC-PLC was heat stable, nonhemolytic for sheep erythrocytes, and active between p H 2 and 8. Western blot analysis with sera from melioidosis patients indica ted that they produced immunoglobulin M antibodies against this PC-PLC prot ein.