Non-ribosomal propeptide precursor in nocardicin A biosynthesis predicted from adenylation domain specificity dependent on the MbtH family protein NocI.

ABSTRACT: Nocardicin A is a monocyclic β-lactam isolated from the actinomycete Nocardia uniformis that shows moderate antibiotic activity against a broad spectrum of gram-negative bacteria. The monobactams are of renewed interest due to emerging gram-negative strains resistant to clinically available penicillins and cephalosporins. Like isopenicillin N, nocardicin A has a tripeptide core of non-ribosomal origin. Paradoxically, the nocardicin A gene cluster encodes two non-ribosomal peptide synthetases (NRPSs), NocA and NocB, predicted to encode five modules pointing to a pentapeptide precursor in nocardicin A biosynthesis, unless module skipping or other nonlinear reactions are occurring. Previous radiochemical incorporation experiments and bioinformatic analyses predict the incorporation of p-hydro

SUBMITTER: Davidsen JM 

PROVIDER: S-EPMC3571714 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature