IDENTIFICATION OF GENES FOR CARDIOLIPIN SYNTHASE IN Pseudomonas putida A ATCC 12633

LOPEZ, G. A.; BOERIS P.S.; HEREDIA R.M.; LUCCHESI, G. I.

Jornada; XIX Annual Scientific Meeting. SOCIEDAD DE BIOLOGÍA DE CÓRDOBA; 2013

Under stress conditions, bacteria respond modificating the content of cardiolipin (CL) of the membrane. The cardiolipin synthase (Cls) catalyzes the condensation of two phosphatidylglycerol molecules to form cardiolipin (CL) and glycerol. The aim of this work was to identify the genes of P. putida ATCC 12633 involved in the synthesis of CL. We have cloned and sequenced two orfs of P. putida A ATCC 12633 that encodes a homologous to cardiolipin synthase genes (cls and cls2) from P. putida KT 2440. Singles and double mutants were obtained. The CL content in the wild type strain and in the single mutants P. putida GP01 (clsΔaacC1 GmR) and P. putida RH01 (cls2Δ::aph(3´)-IIa, KmR) was similar. In the double mutant P. putida RH02 (clsΔaacC1, cls2Δ::aph(3´)-IIa) the CL content represented only 2.9% of total phospholipids. The trace amounts of CL detected in the double mutant could be attributed to the action of phosphatidylserine synthase. The decrease in levels of CL of P. putida RH02 was compensated with a 120% increase in the relative amounts of phosphatidylglycerol, which is consistent with the CL synthesis pathway. Only the cell-free extracts of P. putida RH02 did not contain Cls activity, when it was determined using the fluorescent substrate NBD-PG. These results highlight that in P. putida A ATCC 12633, at least two genes are responsible for the synthesis of CL.