title: [Identification of key residues in the catalytic center JadH involved in binding substrates or catalysis of jadomycin biosynthesis].
abstract: JadH is a bifunctional hydoxylase/dehydrase involved in jadomycin biosynthesis; it catalyzes a post-PKS modification reaction to convert 2,3-dehydro-UWM6 to dehydrorabelomycin. To identify the key residues involved in substrate-binding and catalysis, structural modeling and multiple sequence alignments of JadH homologs were performed to predict nine residues at the proximity of substrate. Site-directed mutagenesis of the corresponding residues and in vitro evaluation of the activities of the mutant enzymes, indicate these mutations severely reduced JadH activity. Our results indicate these residues are specifically involved in substrate-binding or catalysis in JadH.
authors.affiliation: School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Peng
authors.forename: Junjie
authors.initials: J
authors.lastname: Ji
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Keqiang
authors.initials: K
authors.lastname: Fan
authors.forename: Ling
authors.initials: L
authors.lastname: Jin
authors.forename: Yuxiu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Keqian
authors.initials: K
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism*; D007546:Isoquinolines / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000378:metabolism; D009285:Naphthoquinones / Q000378:metabolism*; D013302:Streptomyces / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D007546:Isoquinolines; D050505:Mutant Proteins; D009285:Naphthoquinones; C506597:jadomycin A; C081750:jadomycin B; D006899:Mixed Function Oxygenases; D006836:Hydro-Lyases