圈卷产色链霉菌尼可霉素生物合成基因—sanL的结构与功能

STRUCTURE AND FUNCTION OF sanL GENE INVOLVED IN NIKKOMYCIN BIOSYNTHESIS OF STREPTOMYCES ANSOCHROMOGENES

利用染色体步移策略 ,以尼可霉素生物合成相关的基因片段为探针 ,从圈卷产色链霉菌中克隆到了一个大约 1 0kb的DNA片段。序列分析表明此片段中除含有sanK外 ,在sanK的上游还有一个完整开放阅读框———sanL。sanL与sanK的转录方向相同 ,具有 1 2 81个核苷酸 ,起始密码子为 345位的ATG ,终止密码子为 1 62 3位的TGA。利用Blastx程序进行的分析揭示 ,此基因可能编码一个赖氨酸 2 氨基转移酶。基因功能研究表明 ,该基因是圈卷产色链霉菌尼可霉素生物合成所必需的。

The chromosome walking strategy has been used in this experiment and a 10kb DNA fragment was cloned from the cosmid library of Streptomyces ansochromogenes using a partial DNA fragment involved in the nikkomycin biosynthesis as a probe.The nucleotide sequence showed that the DNA fragment contains two complete open reading frames (ORFs),they are designated as sanK and sanL respectively.The \%sanL\% is located on the upstream of \%sanK\%,it has 1281 nucleotides with ATG at 345 position as start codon and TGA at 623 position as stop codon.The deduced product is L\|lysine 2\|aminotransferase using Blastx program.The experiment of gene disruption indicated that this gene is closely related to nikkomycin biosynthesis of Streptomyces ansochromogenes.