Project description:This study compared the genome of Streptomyces rimosus rimosus against that of Streptomyces coelicolor. It also compared 4 strains with changes in oxytetracycline production and derived from G7, the type strain, against G7. Keywords: Comparative genomic hybridization
Project description:Asymmetric oxidation of prochiral sulfides is a direct means for production of enantiopure sulfoxides which are important in organic synthesis and the pharmaceutical industry. In the present study, Streptomyces glaucescens GLA.0 was employed for stereoselective oxidation of prochiral sulfides. Growing cells selectively catalyzed the oxidation of phenyl methyl sulfide to the corresponding sulfoxide. Only very little overoxidation was observed, resulting in minor amounts of the unwanted sulfone. Addition of isopropyl alcohol as a co-solvent, time of substrate addition and composition of the reaction media resulted in enhanced phenyl methyl sulfide biotransformation. The concentration of the undesired by-product (sulfone) was as low as 4% through the reaction course under optimal reaction conditions. The results show that S. glaucescens GLA.0 is a promising whole-cell biocatalyst for preparing highly enantiopure (R)-phenyl methyl sulfoxide in high yield (90%) with an enantiomeric excess (ee) exceeding 99%.
Project description:We identified genome-wide binding regions of NdgR in Streptomyces coelicolor using chromatin immunoprecipitation sequencing (ChIP-seq). We constructed 6×myc-tagged NdgR strain using homologous recombination with myc-tagging vector. Analysis of the sequencing data aligned to Streptomyces coelicolor genome database (NC_003888).
Project description:Site-directed mutagenesis was used to determine the functional role of several residues of Streptomyces glaucescens tyrosinase. Replacement of His-37, -53, -193 or -215 by glutamine yields albino phenotypes, as determined by expression on melanin-indicator plates. The purified mutant proteins display no detectable oxy-enzyme and increased Cu lability at the binuclear active site. The carbonyl derivatives of H189Q and H193Q luminesce, with lambda max. displaced more than 25 nm to a longer wavelength compared with native tyrosinase. The remaining histidine mutants display no detectable luminescence. The results are consistent with these histidine residues (together with His-62 and His-189 reported earlier) acting as Cu ligands in the Streptomyces glaucescens enzyme. Conservative substitution of the invariant Asn-190 by glutamine also gives an albino phenotype, no detectable oxy-enzyme and labilization of active-site Cu. The luminescence spectrum of carbonyl-N190Q, however, closely resembles that of the native enzyme under conditions promoting double Cu occupancy of the catalytic site. A critical role for Asn-190 in active-site hydrogen-bonding interactions is proposed.