Subunit Composition of B. subtilis RNA Polymerase

Abstract

RECENT evidence indicates that the temporal control of transcription can be regulated by specific initiation factors (σ factors), first characterized by Burgess et al.¹ for the RNA polymerase of Escherichia coli. Our studies indicate the existence of temporal control in the synthesis of the proteins coded by the DNA of Bacillus subtilis phage ϕ29 (unpublished results of E. Méndez, G. Ramirez, M. S., and E. V.). To study the induction of specific σ factor(s) and the control of the transcription of viral DNA after infection of B. subtilis with ϕ29, we purified the RNA polymerase from uninfected cells and report here, first, the isolation of the pure enzyme and, second, its subunit composition.