Abstract: | Superselective affinity labelling of E. coli RNA polymerase in a complex with the promoter-containing fragment of T7 DNA by treatment with orto-formylphenyl ester of GMP followed by addition of [alpha-33P]UTP resulted in covalent binding of the residue--pGpU (p-radioactive phosphate) with one of lysine residues of the beta-subunit, Lys1048, Lys1051, Lys1057, Lys1065. The amino acid sequence of this region of the beta-subunit of E. coli RNA polymerase has a high extent of homology with that deduced for a region of tobacco chloroplast RNA polymerase on the basis of the nucleotide sequence of the chloroplast rpoB-like gene. |