ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
We cloned a new gene, sigH, encoding an alternative σ factor in Streptomyces coelicolor A3(2). The deduced protein of 354 amino acids with an Mr of 39 486 showed greatest similarity to the sporulation σ factor (σF) of S. coelicolor, general stress-response σB of Bacillus subtilis, and stationary-phase stress-response σF of Mycobacterium tuberculosis. Sequence analysis of the upstream region revealed an ORF encoding a protein (UshX) similar to several anti-σ factors, and short ORF (UshY) containing zinc-finger DNA binding motif. Transcriptional analysis revealed that all three genes are located on the same polycistronic transcript in order ushY, ushX, and sigH. Expression of the operon was directed by four promoters differentially expressed in the course of differentiation. The first (P1) constitutive promoter was located upstream of ushY. The other three promoters (P2, P3, and P4) were located upstream of ushX, and were differentially induced after various stress conditions. The magnitude of the induction was greatest after osmotic stress and heat shock.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.2000.tb09202.x
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