Lipoylating and biotinylating enzymes contain a homologous catalytic module

摘要: Biotin and lipoic acid moieties are the covalently attached coenzyme cofactors of several multicomponent enzyme complexes that catalyze key metabolic reactions. Attachment these to biotinyl- lipoyl-dependent enzymes is post-translationally catalyzed by specific biotinylating lipoylating protein enzymes. In Escherichia coli, two different enzymes, LplA LipB, independent pathways for lipoylation relevant whereas only one enzyme, BirA protein, responsible all biotinylation. Counterparts E. coli BirA, LplA, LipB have been previously identified in many organisms, but homology among three families has never reported. Computational analysis based on PSI-BLAST profiles secondary structure predictions indicates, however, evolutionarily related containing a homologous catalytic module. Sequence conservation very poor, single lysine residue strictly conserved them, which, according available X-ray crystal expected contribute binding