title: Damage repair DNA polymerases Y.
abstract: The newly found Y-family DNA polymerases are characterized by low fidelity replication using an undamaged template and the ability to carry out translesion DNA synthesis. The crystal structures of three Y-family polymerases, alone or complexed with DNA and nucleotide substrate, reveal a conventional right-hand-like catalytic core consisting of finger, thumb and palm domains. The finger and thumb domains are unusually small resulting in an open and spacious active site, which can accommodate mismatched base pairs as well as various DNA lesions. Although devoid of a 3'-->5' exonuclease activity, the Y-family polymerases possess a unique "little finger" domain that facilitates DNA association, catalytic efficiency and interactions with auxiliary factors. Expression of Y-family polymerases is often induced by DNA damage, and their recruitment to the replication fork is mediated by beta-clamp, clamp loader, single-strand-DNA-binding protein and RecA in Escherichia coli, and by ubiquitin-modified proliferating cell nuclear antigen in yeast.
authors.affiliation: Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA. Wei.Yang@nih.gov
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
mesh_terms: D001665:Binding Sites; D017124:Conserved Sequence; D003461:Crystallography / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D046911:Macromolecular Substances; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship
chemical_list: D046911:Macromolecular Substances; D004247:DNA; D004259:DNA-Directed DNA Polymerase