Localization of Escherichia coli RNA polymerase binding sites on bacteriophage S13 and phiX174 DNA: alignment with restriction enzyme maps

Abstract

Escherichia coli RNA polymerase has been shown to bind to a limited number of Hind and Hae III restriction enzyme fragments. On S13 replicative form DNA there are three major binding sites, and the locations correlate with promoter sites at the beginning of genes a and B and a site overlapping gene D and the beginning of gene E. Two less definite binding sites have been localized, one in gene F and one at the gene G-H junction. In phiX174 replicative form DNA, five sites, each with apparently similar binding properties, have been located, four of which correspond exactly to binding sites in S13. One site, at the beginning of the B gene, could not be assigned to exactly the same location found in S13. This was due in part to differences in the restriction cleavage maps in the area of the DNA and possibly to the higher background of nonspecific binding in the phiX174 experiments. The location of two of the phiX174 sites at the beginning of genes A and D-E corresponds very well with transcription data, but the site at the start of the B gene indicates the promoter site is closer to the initiation sequence of the B protein than was previously suggested on the basis of transcription data.