title: Tetrameric restriction enzymes: expansion to the GIY-YIG nuclease family.
abstract: The GIY-YIG nuclease domain was originally identified in homing endonucleases and enzymes involved in DNA repair and recombination. Many of the GIY-YIG family enzymes are functional as monomers. We show here that the Cfr42I restriction endonuclease which belongs to the GIY-YIG family and recognizes the symmetric sequence 5'-CCGC/GG-3' ('/' indicates the cleavage site) is a tetramer in solution. Moreover, biochemical and kinetic studies provided here demonstrate that the Cfr42I tetramer is catalytically active only upon simultaneous binding of two copies of its recognition sequence. In that respect Cfr42I resembles the homotetrameric Type IIF restriction enzymes that belong to the distinct PD-(E/D)XK nuclease superfamily. Unlike the PD-(E/D)XK enzymes, the GIY-YIG nuclease Cfr42I accommodates an extremely wide selection of metal-ion cofactors, including Mg2+, Mn2+, Co2+, Zn2+, Ni2+, Cu2+ and Ca2+. To our knowledge, Cfr42I is the first tetrameric GIY-YIG family enzyme. Similar structural arrangement and phenotypes displayed by restriction enzymes of the PD-(E/D)XK and GIY-YIG nuclease families point to the functional significance of tetramerization.
authors: Institute of Biotechnology, Graiciuno 8, LT-02241 Vilnius, Lithuania.
authors: Giedrius
authors: G
authors: Gasiunas
authors: Giedrius
authors: G
authors: Sasnauskas
authors: Gintautas
authors: G
authors: Tamulaitis
authors: Claus
authors: C
authors: Urbanke
authors: Dalia
authors: D
authors: Razaniene
authors: Virginijus
authors: V
authors: Siksnys
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002413:Cations, Divalent / Q000737:chemistry; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D007700:Kinetics; D008670:Metals / Q000737:chemistry; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D002413:Cations, Divalent; D008670:Metals; D004247:DNA; D015252:Deoxyribonucleases, Type II Site-Specific