Parashar Archana, Colvin Kimberley R, Bignell Dawn R D, Leskiw Brenda K
Department of Biological Sciences, CW405 Biological Sciences Building, University of Alberta, Edmonton, Alberta, Canada.
J Bacteriol. 2009 Apr;191(8):2541-50. doi: 10.1128/JB.01695-08. Epub 2009 Feb 6.
The similarity of BldG and the downstream coexpressed protein SCO3548 to anti-anti-sigma and anti-sigma factors, respectively, together with the phenotype of a bldG mutant, suggests that BldG and SCO3548 interact as part of a regulatory system to control both antibiotic production and morphological differentiation in Streptomyces coelicolor. A combination of bacterial two-hybrid, affinity purification, and far-Western analyses demonstrated that there was self-interaction of both BldG and SCO3548, as well as a direct interaction between the two proteins. Furthermore, a genetic complementation experiment demonstrated that SCO3548 antagonizes the function of BldG, similar to other anti-anti-sigma/anti-sigma factor pairs. It is therefore proposed that BldG and SCO3548 form a partner-switching pair that regulates the function of one or more sigma factors in S. coelicolor. The conservation of bldG and sco3548 in other streptomycetes demonstrates that this system is likely a key regulatory switch controlling developmental processes throughout the genus Streptomyces.
BldG与下游共表达蛋白SCO3548分别与抗抗σ因子和抗σ因子相似，再结合bldG突变体的表型，表明BldG和SCO3548作为调控系统的一部分相互作用，以控制天蓝色链霉菌的抗生素产生和形态分化。细菌双杂交、亲和纯化和远Western分析相结合表明，BldG和SCO3548均存在自我相互作用，且这两种蛋白之间存在直接相互作用。此外，遗传互补实验表明，与其他抗抗σ/抗σ因子对类似，SCO3548拮抗BldG的功能。因此，有人提出BldG和SCO3548形成一个伙伴切换对，调节天蓝色链霉菌中一个或多个σ因子的功能。bldG和sco3548在其他链霉菌中的保守性表明，该系统可能是控制整个链霉菌属发育过程的关键调控开关。
