圈卷产色链霉菌7100分化相关基因——sawE的结构与功能

以天蓝色链霉菌的whiB基因为探针，从圈卷产色链霉菌7100的总DNA部分文库中克隆了含有whiB同源序列的28kb DNA片段，并对其中的14kb片段进行了序列测定。序列分析表明，该片段含有一个完整的开放阅读框—sawE。预测的蛋白质结构及同源性分析显示，sawE与天蓝色链霉菌孢子形成早期的关键基因whiB高度同源，编码产物为一个调控蛋白。sawE的破坏使圈卷产色链霉菌7100的分化终止在气生菌丝阶段，在延长培养时间的情况下仍保持白色的表型，菌丝不能分隔，不能形成成熟的灰色孢子，结果表明sawE基因是一个与圈卷产色链霉菌分化有关的重要基因。

Identification and Functional Characterization of sawE--a Gene Involved in Differentiation of Streptomyces ansochromogenes 7100

A 2.8kb DNA fragment including whiB-like gene was cloned from the partial DNA library of Streptomyces ansochromogenes 7100 by using whiB of Streptomyces coelicolor J1501 as a probe. The nucleotide sequence of 1.4kb DNA fragment was determined and analyzed. The result showed that the fragment contains one complete open reading frame-designated sawE. sawE shows strong identity to whiB, an essential gene for early stage of sporulation. The deduced product of sawE gene is a regulatory protein. sawE disruptant was blocked at aerial hyphae stage of Streptomyces ansochromogenes 7100, no sporulation septation, no formation of grey mature spore. Disruptants maintained white phenotype on prolonged incubation. The result indicated that sawE is essential for the morphological differentiation of S. ansochromogenes.