title: The final acylation step in aromatic dithiolopyrrolone biosyntheses: identification and characterization of the first bacterium N-benzoyltransferase from Saccharothrix algeriensis NRRL B-24137.
abstract: The last step in the biosynthesis of dithiolopyrrolone antibiotics was thought to involve the transfer of acyl group from acyl-CoA to pyrrothine/holothin core. In Saccharothrix algeriensis NRRL B-24137, two acyltransferases, an acetyltransferase and a benzoyltransferase were proposed to catalyze this step. We have previously identified, in Sa. algeriensis genome, two open read frames, actA and actB patiently encoded these enzymes. This study focuses primarily on the characterization of the protein encoded by actA. After cloning and expressing of actA in Escherichia coli BL21, the recombinant protein encoded by actA was purified. Selectivity of ActA for pyrrothine/holothin as substrate and different acyl-CoA as co-substrate was evaluated using two acyls-groups, linear and aromatic. The enzyme was shown to prefer aromatic groups over linear groups as donor group; further neither product nor transfer was observed for linear groups. Therefore ActA has been determined to be a pyrrothine/holothin N-benzoyltransferase which can either pyrrothine (Km of 72μM) or holothin (Km of 129.5μM) as substrates and benzoyl-CoA (Km of 348.65 and 395.28μM) as co-substrates for pyrrothine and holothin, respectively. The optimum pH and temperature has been shown to be 8, 40°C, respectively. ActA is the first enzyme characterized as N-benzoyltransferase in bacteria.
authors.affiliation: Université de Toulouse, Laboratoire de Génie Chimique, UMR 5503 (CNRS/INPT/UPS), Département BioSyM, INPT-ENSAT, 1 Avenue de l'Agrobiopôle, B.P. 32607, F-31326 Castanet-Tolosan Cedex 1, France; Université de Lorraine, UMR INRA 1128 Dynamique des génomes et adaptation microbienne (DynAMic), Faculté des Sciences et Technologies, Campus Aiguillettes, BP 239, 54506 Vandoeuvre-lès-Nancy Cedex, France. Electronic address: safwan.saker@inp-toulouse.fr.
authors.forename: S
authors.initials: S
authors.lastname: Saker
authors.affiliation: Université de Toulouse, Laboratoire de Génie Chimique, UMR 5503 (CNRS/INPT/UPS), Département BioSyM, INPT-ENSAT, 1 Avenue de l'Agrobiopôle, B.P. 32607, F-31326 Castanet-Tolosan Cedex 1, France.
authors.forename: S
authors.initials: S
authors.lastname: Chacar
authors.affiliation: Université de Toulouse, Laboratoire de Génie Chimique, UMR 5503 (CNRS/INPT/UPS), Département BioSyM, INPT-ENSAT, 1 Avenue de l'Agrobiopôle, B.P. 32607, F-31326 Castanet-Tolosan Cedex 1, France.
authors.forename: F
authors.initials: F
authors.lastname: Mathieu
mesh_terms: D039903:Actinobacteria / Q000201:enzymology* / Q000235:genetics; D000215:Acylation; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011760:Pyrrolidinones / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D011760:Pyrrolidinones; D011994:Recombinant Proteins; C006361:acetopyrrothine; D000217:Acyltransferases
keywords: Benzoyl-holothin; Benzoyl-pyrrothine; Holothin; N-benzoyltransferase; Pyrrothine; Saccharothrix algeriensis