title: Poly(ADP-ribose) synthetase. The DNA binding domain and the automodification domain.
abstract: Poly(ADP-ribose) synthetase is known to require double-stranded DNA for activity and to be susceptible to automodification with poly(ADP-ribose). This enzyme is cleaved into two fragments by limited proteolysis with papain. Their molecular weights are 74,000 and 46,000, respectively, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The fragment of Mr 46,000 binds to a nicked DNA-cellulose column with the same affinity as that of native enzyme, while the fragment of Mr 74,000 has little affinity for the DNA ligand. When the enzyme previously automodified with [adenine-U-14C]NAD (2 ADP-ribose units incorporated per molecule of enzyme) is digested with papain, the label is detected only in the fragment of Mr 74,000. These results indicate that poly(ADP-ribose) synthetase contains two domains, one acting as the site for binding of DNA and the other acting as the site(s) for accepting poly(ADP-ribose).
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004247:DNA; D007700:Kinetics; D008970:Molecular Weight; D009243:NAD; D009244:NAD+ Nucleosidase / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011485:Protein Binding; D013950:Thymus Gland / Q000201:enzymology
chemical_list: D010446:Peptide Fragments; D009243:NAD; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D009244:NAD+ Nucleosidase