title: Different active sites of mammalian DNA ligases I and II.
abstract: Bovine DNA ligases I and II were adenylylated in the presence of [alpha-32P]ATP and digested with limiting amounts of trypsin or V8 protease. The generation of radioactive peptides of decreasing size was monitored by polyacrylamide gel electrophoresis and autoradiography. Active site peptides obtained by complete proteolytic digestions with trypsin, V8, or Lys-C protease were also compared. The partial digestion products of DNA ligases I and II were entirely different, with no indication of extensive sequence homology. Furthermore, the sequence of the active site region of DNA ligase I is clearly different from that of DNA ligase II. Similar analysis of a third chromatographically distinct mammalian DNA ligase indicated that it is different from DNA ligase I but related to DNA ligase II.
authors.affiliation: Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Hertfordshire, United Kingdom.
authors.forename: E
authors.initials: E
authors.lastname: Roberts
authors.forename: R A
authors.initials: RA
authors.lastname: Nash
authors.forename: P
authors.initials: P
authors.lastname: Robins
authors.forename: T
authors.initials: T
authors.lastname: Lindahl
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D000075223:Poly-ADP-Ribose Binding Proteins; D029867:Xenopus Proteins
chemical_list: D007527:Isoenzymes; C000607892:LIG1 protein, human; D010446:Peptide Fragments; D000075223:Poly-ADP-Ribose Binding Proteins; D029867:Xenopus Proteins; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D010450:Endopeptidases; D011088:DNA Ligases; D000072481:DNA Ligase ATP; C000618816:DNA ligase III alpha protein, Xenopus