Cloning and Characterization of Genes Encoded in dTDP-D-mycaminose Biosynthetic Pathway from a Midecamycin-producing Strain,Streptomyces mycarofaciens  

作　　者：Lina CONG Wolfgang PIEPERSBERG 

机构地区：[1]College of Biology and Food Technology, Dalian Institute of Light Industry, Dalian 116034, China [2]Institute of Chemical Microbiology, Bergische University, D-42097 Wuppertal, Germany

出　　处：《Acta Biochimica et Biophysica Sinica》2007年第3期187-193,共7页生物化学与生物物理学报（英文版）

基　　金：This study was supported by a grant trom the Fitth Framework Program(FP5)of the European Community for Research,Technological Development and Demonstration Activities

摘　　要：Two subclusters from Streptomyces mycarofaciens, a midecamycin producer, were cloned and partially sequenced. One region was located at the 5＇ end of the mid polyketide synthase （PKS） genes and contained the genes midA, midB and midC. The other region was at the 3＇ end of the PKS genes and contained midK, midl and midH. Analysis of the nucleotide sequence revealed that these genes encode dTDP-glucose synthase （midA）, dTDP-glucose dehydratase （midB）, aminotransferase （midC）, methyltransferase （midK）, glycosyltransferase （midⅠ） and an assistant gene （midH）. All of these genes are involved in the biosynthesis of dTDP-D-mycaminose, the first deoxysugar of midecamycin, and in transferring the mycaminose to the midecamycin aglycone in S. mycarofaciens. Similar to gene pairs desⅧ/desⅦ in S. venezuelae and tylMⅢ/tylMⅡ in S. fradiae, the product of midH probably functions as an auxiliary protein required by the MidⅠ protein for efficient glycosyltransfer in midecamycin biosynthesis.Two subclusters from Streptomyces mycarofaciens, a midecamycin producer, were cloned and partially sequenced. One region was located at the 5＇ end of the mid polyketide synthase （PKS） genes and contained the genes midA, midB and midC. The other region was at the 3＇ end of the PKS genes and contained midK, midl and midH. Analysis of the nucleotide sequence revealed that these genes encode dTDP-glucose synthase （midA）, dTDP-glucose dehydratase （midB）, aminotransferase （midC）, methyltransferase （midK）, glycosyltransferase （midⅠ） and an assistant gene （midH）. All of these genes are involved in the biosynthesis of dTDP-D-mycaminose, the first deoxysugar of midecamycin, and in transferring the mycaminose to the midecamycin aglycone in S. mycarofaciens. Similar to gene pairs desⅧ/desⅦ in S. venezuelae and tylMⅢ/tylMⅡ in S. fradiae, the product of midH probably functions as an auxiliary protein required by the MidⅠ protein for efficient glycosyltransfer in midecamycin biosynthesis.

关 键 词：deoxysugar dTDP-D-mycaminose MIDECAMYCIN Streptomyces mycarofaciens 

分 类 号：TQ465.5[化学工程—制药化工] TQ460.38