title: The phosphopantetheinyl transferase KirP activates the ACP and PCP domains of the kirromycin NRPS/PKS of Streptomyces collinus Tü 365.
abstract: The main steps in the biosynthesis of complex secondary metabolites such as the antibiotic kirromycin are catalyzed by modular polyketide synthases (PKS) and/or nonribosomal peptide synthetases (NRPS). During antibiotic assembly, the biosynthetic intermediates are attached to carrier protein domains of these megaenzymes via a phosphopantetheinyl arm. This functional group of the carrier proteins is attached post-translationally by a phosphopantetheinyl transferase (PPTase). No experimental evidence exists about how such an activation of the carrier proteins of the kirromycin PKS/NRPS is accomplished. Here we report on the characterization of the PPTase KirP, which is encoded by a gene located in the kirromycin biosynthetic gene cluster. An inactivation of the kirP gene resulted in a 90% decrease in kirromycin production, indicating a substantial role for KirP in the biosynthesis of the antibiotic. In enzymatic assays, KirP was able to activate both acyl carrier protein and petidyl carrier domains of the kirromycin PKS/NRPS. In addition to coenzyme A (CoA), which is the natural substrate of KirP, the enzyme was able to transfer acyl-phosphopantetheinyl groups to the apo forms of the carrier proteins. Thus, KirP is very flexible in terms of both CoA substrate and carrier protein specificity. Our results indicate that KirP is the main PPTases that activates the carrier proteins in kirromycin biosynthesis.
authors.affiliation: Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Tübingen, Germany.
authors.forename: Marina
authors.initials: M
authors.lastname: Pavlidou
authors.forename: Eva Karoline
authors.initials: EK
authors.lastname: Pross
authors.forename: Ewa Maria
authors.initials: EM
authors.lastname: Musiol
authors.forename: Andreas
authors.initials: A
authors.lastname: Kulik
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wohlleben
authors.forename: Tilmann
authors.initials: T
authors.lastname: Weber
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048630:Polyketide Synthases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011728:Pyridones / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D011728:Pyridones; C082662:phosphopantetheinyl transferase; D048630:Polyketide Synthases; D017855:Transferases (Other Substituted Phosphate Groups); D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase; C008536:mocimycin