title: Crystal structures of an archaeal class II DNA photolyase and its complex with UV-damaged duplex DNA.
abstract: Class II photolyases ubiquitously occur in plants, animals, prokaryotes and some viruses. Like the distantly related microbial class I photolyases, these enzymes repair UV-induced cyclobutane pyrimidine dimer (CPD) lesions within duplex DNA using blue/near-UV light. Methanosarcina mazei Mm0852 is a class II photolyase of the archaeal order of Methanosarcinales, and is closely related to plant and metazoan counterparts. Mm0852 catalyses light-driven DNA repair and photoreduction, but in contrast to class I enzymes lacks a high degree of binding discrimination between UV-damaged and intact duplex DNA. We solved crystal structures of Mm0852, the first one for a class II photolyase, alone and in complex with CPD lesion-containing duplex DNA. The lesion-binding mode differs from other photolyases by a larger DNA-binding site, and an unrepaired CPD lesion is found flipped into the active site and recognized by a cluster of five water molecules next to the bound 3'-thymine base. Different from other members of the photolyase-cryptochrome family, class II photolyases appear to utilize an unusual, conserved tryptophane dyad as electron transfer pathway to the catalytic FAD cofactor.
authors: Faculty of Chemistry, Department of Biochemistry, Philipps University, Marburg, Germany.
authors: Stephan
authors: S
authors: Kiontke
authors: Yann
authors: Y
authors: Geisselbrecht
authors: Richard
authors: R
authors: Pokorny
authors: Thomas
authors: T
authors: Carell
authors: Alfred
authors: A
authors: Batschauer
authors: Lars-Oliver
authors: LO
authors: Essen
mesh_terms: D001105:Archaea / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004249:DNA Damage; D019641:DNA, Archaeal / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D017020:Methanosarcina / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D010802:Phylogeny; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D025941:Protein Interaction Mapping; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D019641:DNA, Archaeal; D004255:Deoxyribodipyrimidine Photo-Lyase