Open AccessPurification and Comparative Properties of the Delta and Sigma Subunits of RNA Polymerase from Bacillus subtilis
Author(s) -
TJIAN Robert,
LOSICK Richard,
PERO Janice,
HINNEBUSH Alan
Publication year - 1977
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1977.tb11376.x
Subject(s) - rna polymerase , transcription (linguistics) , rna dependent rna polymerase , microbiology and biotechnology , polymerase , bacillus subtilis , biology , rna , dna , rna polymerase i , rna polymerase ii , transcription factor ii d , sigma factor , promoter , biochemistry , gene expression , gene , bacteria , genetics , linguistics , philosophy
Bacillus subtilis delta protein is a 21500‐ M r polypeptide that can be isolated in association with RNA polymerase holoenzyme from uninfected bacteria and with modified forms of RNA polymerase from cells infected with phage SP01 [Pero, J., Nelson, J. and Fox, T. (1975) Proc. Natl Acad. Sci. U.S.A. 72 , 1589]. Although no function has been assigned to δ protein in uninfected cells, this host polypeptide enhances the specificity of transcription by phage‐modified forms of RNA polymerase that contain SP01‐coded regulatory subunits. This report describes the purification of δ and σ proteins from uninfected B. subtilis and examines the comparative effects of these polypeptides on transcription by core RNA polymerase. Purified σ polypeptide was found to stimulate the transcription of phage DNA while having little effect on RNA synthesis with the synthetic DNA poly(dA‐dT) as template. In contrast, purified δ protein markedly depressed the transcription of poly(dA‐dT) while having little effect on enzyme activity with phage DNA as template. The inhibitory effect of δ protein on poly(dA‐dT) transcription was strongly dependent on the presence of KCl in the RNA synthesis reaction mixture.