Detection On Gene Function Of The Caffeoyl CoA-O-methyltransferases From Streptomyces Virginiae IBL-14

S. virginiae IBL-14is a new strain that can degeade diosgenin and other steroids efficiently, which separated and screened by our laboratory. Previous research on the metabolic pathway of diosgenin shows that it has two novel functions, which were the tertiary carbon hydroxylation at C25and the methoxylation at C6.And the methoxylation at C6is the focus of this study. By analysing the results of the whole genome sequencing on IBL-14, we predict that Caffeoyl-CoA O-methyltransferases from IBL-14may involve in the methoxylation at C6.So there are very important to reveal mechanism on C6methoxylation from the studies to these enzymes.This project we screened three genes of Caffeoyl-CoA O-methyltransferase for their enzymatic properties research and some results are as follows:(1) Three recombinant strains of Caffeoyl-CoA O-methyltransferase with the host of Escherichia coli JM109(DE3) have been constructed successfully. From the analysis of fermentation products after adding caffeic acid as the substrate, their activity and function have been identified.(2) Their enzymatic properties have been predicted by bioinformatics methods, such as amino acid composition, isoelectric point, molecular weight, hydrophobicity, secondary structure, space structure and the construction of phylogenetic tree.(3) The subsequent structure optimization was done by molecular dynamics.In conclusion, this paper have researched the enzymatic properties of Caffeoyl-CoA O-methyltransferases in order to reveal mechanism on C6methoxylation on metabolic pathway of diosgenin in S. virginiae IBL-14.