摘要
利用与麦迪霉素生物合成有类似途径的放线紫红素聚酮缩合酶基因Act I作为探针,将来源于麦迪霉素产生菌基因文库的与Act I有同源性的阳性初级克隆pCN8B12进一步缩小,亚克隆获得了2.4kb的麦迪霉素聚酮缩合酶基因,将其插入pWHM3载体中构建了重组质粒pCG2 DNA。pCG2 DNA在放线紫红素聚酮缩合酶基因缺陷型变株天蓝色链霉菌TK17及螺旋霉素产生菌S.ambofaciens中均获得表达。前者所得产物不同于麦迪霉素和放线紫红素,可能为新的杂合抗生素;后者能使螺旋霉素产量得到提高。另外pCG2 DNA在道诺红霉素产生菌调节变株S.peucetius H6101中的表达产物经TLC及HPLC分析表明为紫红霉酮。pCG2 DNA在Tetracenomycin C产生菌S.glaucescens中亦有一定的功能表达,而在红霉素产生菌红霉内酯阻断变株Saccharapolyspora erythraea WMH15,261中未观察到活性表达。推测pCG2 DNA具有一定调节或在某些聚酮类抗生素产生菌变株中起互补的功能。
The midecamycin polyketide condensing enzyme gene derived fromcloned DNA pCN8B12 in genomic library of midecamycin-producing strainStreptomyces mycarofaciens 1748 was subcloned on to the E.coli-Strep-tomyces shuttle vector pWHM3. A recombinant plasmid DNA pCG2 wasobtained and introduced into an ActI^- mutant of actinorhodin producerS. coelicolor TK17, the transformants containing the recombinant plas-mid produced new hybrid antibiotic which different from midecamycinand actinorhodin by paper chromatographic analysis.The transformants ofpCG2 DNA in S.ambofaciens showed increased production of spiramycin.The transformants of pCG2 DNA in a regulatory mutant of daunorubicinproducer S. peucetius H6101 produced a daunorubicin intermediate ε-rhodomycinone, according to TLC and HPLC analysis. The tetracenomy-cin producer S. glaucescens containing pCG2 DNA also exhibited certainantibacterial activity, but transformants of pCG2 DNA in Saccharapolys-pora erythraea WMH 15,261 showed no antibacterial proaucing activity.Presumably the pCG2 DNA showed a regulatory function or ability torestore antibiotic productivity in certain polyketide synthase deficientmutants.
出处
《生物工程学报》
CAS
CSCD
北大核心
1991年第4期291-299,共9页
Chinese Journal of Biotechnology
关键词
麦迪霉素
聚酮缩合酶
基因
亚克隆
Midecamycin
polyketide condensing enzyme gene
hybrid antibiotic
