[Structure of ADP-ribosylating enzyme and DNA repair].

ADP-ribosylation is a post-translational modification of protein using a respiratory coenzyme, NAD+, as a substrate. Poly(ADP-ribosyl)ation reaction in the nuclei has been thought to be involved in DNA repair. Cloning of poly(ADP-ribose)polymerase cDNA and gene has opened the way for analyzing the structure and functions of poly(ADP-ribose)polymerase at the molecular level. Poly(ADP-ribose)polymerase is a zinc-finger protein and binds to nicks of DNA. This enzyme is activated by binding to DNA and poly(ADP-ribosyl)ates nuclear proteins and poly(ADP-ribose)polymerase itself. Structural analysis of poly(ADP-ribose)polymerase from different classes has shown conserved motifs in the domain structures. In this review, recent advances in this field, including mono-ADP-ribosylation and cyclic ADP-ribose, are described.