WhiA, a protein of unknown function conserved among gram-positive bacteria, is essential for sporulation in Streptomyces coelicolor A3(2)
WhiA, a protein of unknown function conserved among gram-positive bacteria, is essential for sporulation in Streptomyces coelicolor A3(2)
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DOI：
10.1128/jb.182.19.5470-5478.2000
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发表时间：
2000-10-01
影响因子：
3.2
通讯作者：
Chater, KF
中科院分区：
文献类型：
--
作者：
Ainsa, JA;Ryding, NJ;Chater, KF
coelicolor链霉菌A3(2)的whiA产孢基因在将空气菌丝从持续延伸生长转向孢子分离的过程中起着关键作用，通过whiA突变体的互补克隆，对野生型等位基因和5个whiA突变体的DNA测序证实，whiA基因编码的蛋白在所有已知的革兰氏阳性菌的基因组序列中都具有同源性。无论是高还是低的G+C含量，这些wha样蛋白都没有任何功能。在大多数情况下，如S， coelicolor，在一个类似操纵子的簇中，wha样基因位于其他保守基因的下游。对构建的断裂突变体的表型分析证实，whiA对孢子形成至关重要。whiA至少由两个启动子转录，其中最下游的启动子位于前一个基因内，当菌落发生孢子形成时，该启动子被强烈上调。上调依赖于功能性whiA基因，提示正向的自我调节，尽管不知道这是直接的还是间接的。与其他一些产孢调控基因的启动子不同，whiA启动子不依赖于whg编码的产孢特异性sigma因子。
The whiA sporulation gene of Streptomyces coelicolor A3(2), which plays a key role in switching aerial hyphae away from continued extension growth and toward sporulation septation, was cloned by complementation of whiA mutants, DNA sequencing of the wild-type allele and five whiA mutations verified that whiA is a gene encoding a protein with homologues in all gram-positive bacteria whose genome sequence is known, whether of high or low G+C content No function has been attributed to any of these WhiA-like proteins. In most cases, as in S, coelicolor, the whiA-like gene is downstream of other conserved genes in an operon-like cluster. Phenotypic analysis of a constructed disruption mutant confirmed that whiA is essential for sporulation. whiA is transcribed from at least two promoters, the most downstream of which is located within the preceding gene and is strongly up-regulated when colonies are undergoing sporulation. The up-regulation depends on a functional whiA gene, suggesting positive autoregulation, although it is not known whether this is direct or indirect. Unlike the promoters of some other sporulation-regulatory genes, the whiA promoter does not depend on the sporulation-specific sigma factor encoded by whiG.