5du9

Publication Abstract from PubMed

Nonribosomal peptide synthetases (NRPSs) synthesize a vast variety of small molecules, including antibiotics, antitumors, and immunosuppressants. The NRPS condensation (C) domain catalyzes amide bond formation, the central chemical step in nonribosomal peptide synthesis. The catalytic mechanism and substrate determinants of the reaction are under debate. We developed chemical probes to structurally study the NRPS condensation reaction. These substrate analogs become covalently tethered to a cysteine introduced near the active site, to mimic covalent substrate delivery by carrier domains. They are competent substrates in the condensation reaction and behave similarly to native substrates. Co-crystal structures show C domain-substrate interactions, and suggest that the catalytic histidine's principle role is to position the alpha-amino group for nucleophilic attack. Structural insight provided by these co-complexes also allowed us to alter the substrate specificity profile of the reaction with a single point mutation.

Chemical Probes Allow Structural Insight into the Condensation Reaction of Nonribosomal Peptide Synthetases.,Bloudoff K, Alonzo DA, Schmeing TM Cell Chem Biol. 2016 Mar 17;23(3):331-9. doi: 10.1016/j.chembiol.2016.02.012. PMID:26991102^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.