Chromosomal organization analysis of genes surrounding Pseudomonas aeruginosa pchp

MASSIMELLI, MJ; BEASSONI, PR; FORRELLAD, MA; BROLL, A; GARRIDO, MN; DOMENECH, CE; LISA, AT

Tafi del Valle, Tucuman

Congreso; XXI Reunión anual de la Sociedad de Biología de Tucumán (SBT); 2004

Sociedad de Biología de Tucuman

The pchP gene, which encodes the enzyme Phosphorylcholine phosphatase (PChP), is located at region 5858257 to 5957208 of P. aeruginosa PAO1 genome. Upstream and downstream of pchP a putative LysR regulator (PA5293) and a probable choline transporter (PA5291) are located, respectively. Northern blot analysis suggested that pchP is transcripted monocistronically, then no operon would relate these genes. Then, we studied if a mutation on PA5291 or PA5293 would affect PChP activity. We measured PChP activity in mutants 42488 (PA5293::ISphoA/hah) and 55818 (PA5291::ISphoA/hah) from UWGC mutant collection. Both strains showed around 70% depletion activity. Introduction of PA5293 and PA5291 wild type genes in pBBR1MCS-5 vector partially restored PChP activity. This suggested that these genes would be related physiologically to pchP, but not included in the same operon. In the other hand, and since pchP is highly conserved in other Pseudomonas species, the organization of this chromosomal region was compared with the equivalent region of these species. We observed that P. putida, P. syringae, and P. fluorescens regions are similar but completely different from P. aeruginosa equivalent region