ADP-ribosylation of DNA-dependent RNA polymerase of Escherichia coli by an NAD+: protein ADP-ribosyltransferase from bacteriophage T4.
A protein from bacteriophage T4 responsible for the alteration of host DNA-dependent RNA polymerase and absent in T4 alt- phage was purified from T4 phage and enriched from T4-infected cells. It is injected during infection together with the known internal proteins. It has a molecular weight of about 70000 and catalyses the release of nicotinamide and the transfer of the ADP-ribosyl moiety from NAD+ to arginyl residues of various proteins including itself. RNA polymerase from Escherichia coli accepts ADP-ribosyl residues in all four subunits; the alpha subunit reacts with very high specificity. Only half of the alpha subunits are labelled, 45% with one, 5% with two residues. The main product shows the same electrophoretic mobility as alpha subunits altered or modified in vivo. The alpha subunit in modified RNA polymerase is no acceptor.
D001426:Bacterial Proteins / Q000378:metabolism; D003090:Coliphages / Q000201:enzymology*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D009113:Muramidase; D009154:Mutation; D009243:NAD; D009536:Niacinamide / Q000494:pharmacology; D009994:Osmolar Concentration; D010430:Pentosyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism
D001426:Bacterial Proteins; D014764:Viral Proteins; D009243:NAD; D009536:Niacinamide; D010430:Pentosyltransferases; D012321:DNA-Directed RNA Polymerases; D009113:Muramidase