SYMPOSIA

MI-S01 ENZYMATIC DIVERSITY IN LIPOIC ACID MODIFICATION OF PROTEINS Mansilla MC,Martin N,de Mendoza D.Instituto de Biología Molecular y Celular de Rosario(IBR-CONICET),Univ.Nac.de Rosario,Rosario,Argentina Lipoic acid(LA)is a covalently bound cofactor essential for the function of several key enzymes involved in oxidative and single carbon metabolism.The genes for LA synthesis were initially identified in Escherichia coli,and the current model for protein lipoylation is based in the mechanism employed by this bacterium.It involves two pathways:one in which exogenous LA is transferred to apoproteins in a process mediated by LA ligase(LplA),and an endogenous one,that involves LipB,which transfers octanoate to target proteins.These octanoylated domains are converted into lipoylated derivatives by lipoyl synthase(LipA).