title: Cloning and characterization of the gene encoding 1-cyclohexenylcarbonyl coenzyme A reductase from Streptomyces collinus.
abstract: We report the cloning of the gene encoding the 1-cyclohexenylcarbonyl coenzyme A reductase (ChcA) of Streptomyces collinus, an enzyme putatively involved in the final reduction step in the formation of the cyclohexyl moiety of ansatrienin from shikimic acid. The cloned gene, with a proposed designation of chcA, encodes an 843-bp open reading frame which predicts a primary translation product of 280 amino acids and a calculated molecular mass of 29.7 kDa. Highly significant sequence similiarity extending along almost the entire length of the protein was observed with members of the short-chain alcohol dehydrogenase superfamily. The S. collinus chcA gene was overexpressed in Escherichia coli by using a bacteriophage T7 transient expression system, and a protein with a specific ChcA activity was detected. The E. coli-produced ChcA protein was purified and shown to have similar steady-state kinetics and electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gels as the enoyl-coenzyme A reductase protein prepared from S. collinus. The enzyme demonstrated the ability to catalyze, in vitro, three of the reductive steps involved in the formation of cyclohexanecarboxylic acid. An S. collinus chcA mutant, constructed by deletion of a genomic region comprising the 5' end of chcA, lost the ChcA activity and the ability to synthesize either cyclohexanecarboxylic acid or ansatrienin. These results suggest that chcA encodes the ChcA that is involved in catalyzing multiple reductive steps in the pathway that provides the cyclohexanecarboxylic acid from shikimic acid.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, 21201, USA.
authors.forename: P
authors.initials: P
authors.lastname: Wang
authors.forename: C D
authors.initials: CD
authors.lastname: Denoya
authors.forename: M R
authors.initials: MR
authors.lastname: Morgenstern
authors.forename: D D
authors.initials: DD
authors.lastname: Skinner
authors.forename: K K
authors.initials: KK
authors.lastname: Wallace
authors.forename: R
authors.initials: R
authors.lastname: Digate
authors.forename: S
authors.initials: S
authors.lastname: Patton
authors.forename: N
authors.initials: N
authors.lastname: Banavali
authors.forename: G
authors.initials: G
authors.lastname: Schuler
authors.forename: M K
authors.initials: MK
authors.lastname: Speedie
authors.forename: K A
authors.initials: KA
authors.lastname: Reynolds
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D003509:Cyclohexanecarboxylic Acids / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D044943:Fatty Acid Desaturases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010641:Phenotype; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017384:Sequence Deletion; D012765:Shikimic Acid / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D003509:Cyclohexanecarboxylic Acids; D011994:Recombinant Proteins; D012765:Shikimic Acid; D044943:Fatty Acid Desaturases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C074885:1-cyclohexenylcarbonyl-CoA reductase, Streptomyces collinus; C044895:cyclohexanecarboxylic acid