BldG and SCO3548 interact antagonistically to control key developmental processes in Streptomyces coelicolor.
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.
Parashar
Archana
A
Department of Biological Sciences, CW405 Biological Sciences Building, University of Alberta, Edmonton, Alberta, Canada.
Colvin
Kimberley R
KR
Bignell
Dawn R D
DR
Leskiw
Brenda K
BK
D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D026481:Blotting, Far-Western; D002846:Chromatography, Affinity; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D011485:Protein Binding; D025941:Protein Interaction Mapping; D048372:Streptomyces coelicolor / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D020798:Two-Hybrid System Techniques
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins