title: 4'-phosphopantetheine transfer in primary and secondary metabolism of Bacillus subtilis.
abstract: 4'-Phosphopantetheine transferases (PPTases) transfer the 4'-phosphopantetheine moiety of coenzyme A onto a conserved serine residue of acyl carrier proteins (ACPs) of fatty acid and polyketide synthases as well as peptidyl carrier proteins (PCPs) of nonribosomal peptide synthetases. This posttranslational modification converts ACPs and PCPs from their inactive apo into the active holo form. We have investigated the 4'-phosphopantetheinylation reaction in Bacillus subtilis, an organism containing in total 43 ACPs and PCPs but only two PPTases, the acyl carrier protein synthase AcpS of primary metabolism and Sfp, a PPTase of secondary metabolism associated with the nonribosomal peptide synthetase for the peptide antibiotic surfactin. We identified and cloned ydcB encoding AcpS from B. subtilis, which complemented an Escherichia coli acps disruption mutant. B. subtilis AcpS and its substrate ACP were biochemically characterized. AcpS also modified the d-alanyl carrier protein but failed to recognize PCP and an acyl carrier protein of secondary metabolism discovered in this study, designated AcpK, that was not identified by the Bacillus genome project. On the other hand, Sfp was able to modify in vitro all acyl carrier proteins tested. We thereby extend the reported broad specificity of this enzyme to the homologous ACP. This in vitro cross-interaction between primary and secondary metabolism was confirmed under physiological in vivo conditions by the construction of a ydcB deletion in a B. subtilis sfp(+) strain. The genes coding for Sfp and its homolog Gsp from Bacillus brevis could also complement the E. coli acps disruption. These results call into question the essential role of AcpS in strains that contain a Sfp-like PPTase and consequently the suitability of AcpS as a microbial target in such strains.
authors.affiliation: Philipps-Universität Marburg, Fachbereich Chemie/Biochemie, Hans-Meerwein-Str., Marburg D-35032, Germany.
authors.forename: H D
authors.initials: HD
authors.lastname: Mootz
authors.forename: R
authors.initials: R
authors.lastname: Finking
authors.forename: M A
authors.initials: MA
authors.lastname: Marahiel
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D010204:Pantetheine / Q000031:analogs & derivatives* / Q000378:metabolism*; D010940:Plant Proteins; D017386:Sequence Homology, Amino Acid; D017855:Transferases (Other Substituted Phosphate Groups) / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; C085651:D-alanyl carrier protein, bacteria; D047908:Intracellular Signaling Peptides and Proteins; C119296:PCP protein, Brassica napus; D010940:Plant Proteins; C042469:alanine-carrier protein, bacteria; C082662:phosphopantetheinyl transferase; D010204:Pantetheine; D017855:Transferases (Other Substituted Phosphate Groups); C003129:4'-phosphopantetheine