Post-translational Claisen Condensation and Decarboxylation en Route to the Bicyclic Core of Pantocin A.

ABSTRACT: Pantocin A (PA) is a member of the growing family of ribosomally encoded and post-translationally modified peptide natural products (RiPPs). PA is much smaller than most known RiPPs, a tripeptide with a tight bicyclic core that appears to be cleaved from the middle of a larger 30-residue precursor peptide. We show here that the enzyme PaaA catalyzes the double dehydration and decarboxylation of two glutamic acid residues in the 30-residue precursor PaaP. Further truncates of PaaP leader and follower peptide sequences demonstrate the different impacts of these two regions on PaaA-mediated tailoring and delineate an essential role for the follower sequence in the decarboxylation step. The crystal structure of apo PaaA is reported, allowing identification of structural features that set PaaA

SUBMITTER: Ghodge SV 

PROVIDER: S-EPMC4955399 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature