title: Mutational analysis reveals that all tailoring region genes are required for production of polyketide antibiotic mupirocin by pseudomonas fluorescens: pseudomonic acid B biosynthesis precedes pseudomonic acid A.
abstract: The Pseudomonas fluorescens mupirocin biosynthetic cluster encodes six proteins involved in polyketide biosynthesis and 26 single polypeptides proposed to perform largely tailoring functions. In-frame deletions in the tailoring open reading frames demonstrated that all are required for mupirocin production. A bidirectional promoter region was identified between mupF, which runs counter to other open reading frames and its immediate neighbor macpC, implying the 74-kb cluster consists of two transcriptional units. mupD/E and mupJ/K must be cotranscribed as pairs for normal function implying co-assembly during translation. MupJ and K belong to a widely distributed enzyme pair implicated, with MupH, in methyl addition. Deletion of mupF, a putative ketoreductase, produced a mupirocin analogue with a C-7 ketone. Deletion of mupC, a putative dienoyl CoA reductase, generated an analogue whose structure indicated that MupC is also implicated in control of the oxidation state around the tetrahydropyran ring of monic acid. Double mutants with DeltamupC and DeltamupO, DeltamupU, DeltamupV, or DeltamacpE produced pseudomonic acid B but not pseudomonic acid A, as do the mupO, U, V, and macpE mutants, indicating that MupC must work after MupO, U, and V.
authors: School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors: Joanne
authors: J
authors: Hothersall
authors: Ji'en
authors: J
authors: Wu
authors: Ayesha S
authors: AS
authors: Rahman
authors: Jennifer A
authors: JA
authors: Shields
authors: James
authors: J
authors: Haddock
authors: Nicola
authors: N
authors: Johnson
authors: Sian M
authors: SM
authors: Cooper
authors: Elton R
authors: ER
authors: Stephens
authors: Russell J
authors: RJ
authors: Cox
authors: John
authors: J
authors: Crosby
authors: Christine L
authors: CL
authors: Willis
authors: Thomas J
authors: TJ
authors: Simpson
authors: Christopher M
authors: CM
authors: Thomas
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence / Q000235:genetics*; D005227:Fatty Acids / Q000096:biosynthesis / Q000235:genetics; D005798:Genes, Bacterial; D018942:Macrolides / Q000378:metabolism*; D008745:Methylation; D005810:Multigene Family; D016712:Mupirocin / Q000096:biosynthesis*; D016366:Open Reading Frames; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000201:enzymology / Q000235:genetics*; D017384:Sequence Deletion
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D018942:Macrolides; C014246:pseudomonic acid I; D016712:Mupirocin; D010088:Oxidoreductases