title: Genes encoding acyl-CoA dehydrogenase (AcdH) homologues from Streptomyces coelicolor and Streptomyces avermitilis provide insights into the metabolism of small branched-chain fatty acids and macrolide antibiotic production.
abstract: The cloning, using a PCR approach, of genes from both Streptomyces coelicolor and Streptomyces avermitilis encoding an acyl-CoA dehydrogenase (AcdH), putatively involved in the catabolism of branched-chain amino acids, is reported. The deduced amino acid sequences of both genes have a high similarity to prokaryotic and eukaryotic short-chain acyl-CoA dehydrogenases. When the S. coelicolor and S. avermitilis acyl-CoA dehydrogenase genes (acdH) were expressed in Escherichia coli, each of the AcdH flavoproteins was able to oxidize the branched-chain acyl-CoA derivatives isobutyryl-CoA, isovaleryl-CoA and cyclohexylcarbonyl-CoA, as well as the short straight-chain acyl-CoAs n-butyryl-CoA and n-valeryl-CoA in vitro. NMR spectral data confirmed that the oxidized product of isobutyryl-CoA is methacrylyl-CoA, which is the expected product at the acyl-CoA dehydrogenase step in the catabolism of valine in streptomycetes. Disruption of the S. avermitilis acdH produced a mutant unable to grow on solid minimal medium containing valine, isoleucine or leucine as sole carbon sources. Feeding studies with 13C triple-labelled isobutyrate revealed a significant decrease in the incorporation of label into the methylmalonyl-CoA-derived positions of avermectin in the acdH mutant. In contrast the mutation did not affect incorporation into the malonyl-CoA-derived positions of avermectin. These results are consistent with the acdH gene encoding an acyl-CoA dehydrogenase with a broad substrate specificity that has a role in the catabolism of branched-chain amino acids in S. coelicolor and S. avermitilis.
authors.affiliation: School of Pharmacy1 and Department of Bacteriology2, University of Wisconsin, 425 N. Charter St, Madison, WI 53706, USA.
authors.forename: Ying-Xin
authors.initials: YX
authors.lastname: Zhang
authors.affiliation: Bioprocess Research, Central Research Division, Pfizer Inc., Groton, CT 06340, USA3.
authors.forename: Claudio D
authors.initials: CD
authors.lastname: Denoya
authors.affiliation: Bioprocess Research, Central Research Division, Pfizer Inc., Groton, CT 06340, USA3.
authors.forename: Deborah D
authors.initials: DD
authors.lastname: Skinner
authors.affiliation: Bioprocess Research, Central Research Division, Pfizer Inc., Groton, CT 06340, USA3.
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Fedechko
authors.affiliation: Bioprocess Research, Central Research Division, Pfizer Inc., Groton, CT 06340, USA3.
authors.forename: Hamish A I
authors.initials: HAI
authors.lastname: McArthur
authors.affiliation: Bioprocess Research, Central Research Division, Pfizer Inc., Groton, CT 06340, USA3.
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Morgenstern
authors.affiliation: Bioprocess Research, Central Research Division, Pfizer Inc., Groton, CT 06340, USA3.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Davies
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23219, USA4.
authors.forename: Sandra
authors.initials: S
authors.lastname: Lobo
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23219, USA4.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Reynolds
authors.affiliation: School of Pharmacy1 and Department of Bacteriology2, University of Wisconsin, 425 N. Charter St, Madison, WI 53706, USA.
authors.forename: C Richard
authors.initials: CR
authors.lastname: Hutchinson
mesh_terms: D042964:Acyl-CoA Dehydrogenase; D044944:Acyl-CoA Dehydrogenases / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005227:Fatty Acids / Q000378:metabolism*; D017353:Gene Deletion; D006801:Humans; D007559:Ivermectin / Q000031:analogs & derivatives / Q000378:metabolism; D018942:Macrolides; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D051381:Rats; D017422:Sequence Analysis, DNA; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D005227:Fatty Acids; D018942:Macrolides; D007559:Ivermectin; C019264:avermectin; D044944:Acyl-CoA Dehydrogenases; D042964:Acyl-CoA Dehydrogenase