IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Identification, distribution and regulation of PhlAEa, A type-A phospholipase from E. aerogenes
Autor/es:
FEDRIGO, G. V; CASTELLI, M. E.; ALTABE, S. E.; GARCÍA VÉSCOVI, E.
Lugar:
Rosario, Argentina
Reunión:
Congreso; 42th Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2006
Institución organizadora:
Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular
Resumen:
Enterobacter is an opportunistic pathogen associated to nosocomial infections. We selected an E. aerogenes isolate from an Enterobacter clinical collection strain that exhibited marked extracellular lipolytic activity. We identified that this exoprotein corresponded to a type A phospholipase (phlAEa) with high homology to phospholipases present in Serratia, Yersinia, Xanthomonas and Photorhabdus (E. aerogenes has no available genome database). By sourthern-blot analysis we showed that this locus was present only in some strains of our Enterobacter collection suggesting that this genomic region was subjected to DNA rearrangement processes. We determined the transcription initiation site for phlAEa by primer extention. The putative phlAEa promoter region showed sequences that matched to predicted cAMP-CRP and sF recognition motifs. We analyzed phlAEa expression by measuring lipolytic activity and transcriptional regulation by ¥â-galactosidase activity from a phlAEa::lacZ fusion. We observed that phlAEa expression was regulated by catabolite repression and induced when bacteria were grown at 30¨¬C. phlAEa transcriptional levels were abolished in an E. coli flhD strain consistent with the sF-regulatory-dependence. In addition we showed that the expression of the flagella was required for PhlAEa to be exported.