title: Concerted action of P450 plus helper protein to form the amino-hydroxy-piperidone moiety of the potent protease inhibitor crocapeptin.
abstract: The crocapeptins are described here as cyclic depsipeptides, isolated from cultures of the myxobacterium Chondromyces crocatus . Structure elucidation of the compounds revealed a cyanopeptolin-like skeleton, containing the characteristic amino-hydroxy-piperidone (Ahp)-heterocycle. Like the cyanopeptolins, the myxobacterial crocapeptins proved to be serine protease inhibitors. The nonribosomal origin of the peptide was confirmed by mutagenesis experiments, and the biosynthesis gene cluster was sequenced. It could be shown that the Ahp-heterocycle originates from a proline residue in the precursor molecule precrocapeptin, which is converted to crocapeptin by the tailoring enzymes CpnE and CpnF. Conversion of precrocapeptin isolated from a cpnF mutant into crocapeptin was achieved using recombinant CpnF, a cytochrome P450 enzyme responsible for hydroxylation of the proline residue in precrocapeptin. Addition of protein CpnE resulted in strongly increased conversion rates toward Ahp containing product. A mutant with 10-fold increased production of crocapeptin A was created through insertion of the Pnpt-promotor in front of the NRPS gene.
authors.affiliation: Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, and Department of Pharmaceutical Biotechnology, Saarland University , Building C 2.3, D-66123, Saarbrücken, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Viehrig
authors.forename: Frank
authors.initials: F
authors.lastname: Surup
authors.forename: Kirsten
authors.initials: K
authors.lastname: Harmrolfs
authors.forename: Rolf
authors.initials: R
authors.lastname: Jansen
authors.forename: Brigitte
authors.initials: B
authors.lastname: Kunze
authors.forename: Rolf
authors.initials: R
authors.lastname: Müller
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D047630:Depsipeptides / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006900:Hydroxylation; D005810:Multigene Family; D009154:Mutation; D009231:Myxococcales / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D010881:Piperidones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D047630:Depsipeptides; D010881:Piperidones; D015842:Serine Proteinase Inhibitors; D003577:Cytochrome P-450 Enzyme System