title: The ADP-ribosyltransferases (gpAlt) of bacteriophages T2, T4, and T6: sequencing of the genes and comparison of their products.
abstract: The Alt gene product is a component of the T4 phage head. Upon infection of the host cell, approximately 40 copies of the Alt protein enter the cell together with the viral DNA molecule. The Alt protein then ADP-ribosylates one of the two alpha-subunits of host RNA polymerase. A restriction fragment harboring the ADP-ribosyltransferase gene of bacteriophage T4 was cloned into the plasmid vector pBluescript, the nucleotide sequence was determined, and the reading frame was identified. Two M13 clone libraries, established with DNA isolated from bacteriophages T2 and T6, then were screened for the corresponding genes. The nucleotide sequences of the three alt genes and the deduced amino acid sequences were compared. Secondary structure predictions and NAD-binding studies resulted in the location of the substrate-binding site in the NH2-terminal regions of the enzymes.
authors.affiliation: Arbeitsgruppe Molekulare Genetik, Lehrstuhl Biologie der Mikroorganismen, Ruhr-Universität Bochum, Federal Republic of Germany.
authors.forename: T
authors.initials: T
authors.lastname: Koch
authors.forename: W
authors.initials: W
authors.lastname: Rüger
mesh_terms: D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D008969:Molecular Sequence Data; D017900:Myoviridae / Q000201:enzymology* / Q000235:genetics; D016366:Open Reading Frames; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000235:genetics*; D013604:T-Phages / Q000201:enzymology* / Q000235:genetics
chemical_list: D011065:Poly(ADP-ribose) Polymerases