In vivo and in vitro phosphorylation of DNA-dependent RNA polymerase of Escherichia coli by bacteriophage-T7-induced protein kinase.

ABSTRACT

After infection with bacteriophage T7 the beta' and to a lesser extent the beta subunits of E. coli DNA-dependent RNA polymerase (nucleosidetriphosphateRNA nucleotidyltransferase, EC 2.7.7.6) are phosphorylated by a phage-gene-encoded protein kinase (ATPprotein phosphotransferase, EC 2.7.1.37). The phosphorylation occurs on threonine residues and appears site-specific. It is probably the molecular basis of the early transcriptional control.