title: Expression, purification and crystallization of two endonuclease III enzymes from Deinococcus radiodurans.
abstract: Endonuclease III is a bifunctional DNA glycosylase that removes a wide range of oxidized bases in DNA. Deinococcus radiodurans is an extreme radiation-resistant and desiccation-resistant bacterium and possesses three genes encoding endonuclease III enzymes in its genome: DR2438 (EndoIII-1), DR0289 (EndoIII-2) and DR0982 (EndoIII-3). Here, EndoIII-1 and an N-terminally truncated form of EndoIII-3 (EndoIII-3Δ76) have been expressed, purified and crystallized, and preliminary X-ray crystallographic analyses have been performed to 2.15 and 1.31 Å resolution, respectively. The EndoIII-1 crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 181.38, b = 38.56, c = 37.09 Å, β = 89.34° and one molecule per asymmetric unit. The EndoIII-3Δ76 crystals also belonged to the monoclinic space group C2, but with unit-cell parameters a = 91.47, b = 40.53, c = 72.47 Å, β = 102.53° and one molecule per asymmetric unit. The EndoIII-1 structure was determined by molecular replacement, while the truncated EndoIII-3Δ76 structure was determined by single-wavelength anomalous dispersion phasing. Refinement of the structures is in progress.
authors.affiliation: Chemistry Department, NorStruct, UiT The Arctic University of Norway, Forskningsparken 3, 9037 Tromsø, Norway.
authors.forename: Aili
authors.initials: A
authors.lastname: Sarre
authors.affiliation: Structural Biology Group, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Mats
authors.initials: M
authors.lastname: Ökvist
authors.affiliation: Structural Biology Group, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Tobias
authors.initials: T
authors.lastname: Klar
authors.affiliation: Chemistry Department, NorStruct, UiT The Arctic University of Norway, Forskningsparken 3, 9037 Tromsø, Norway.
authors.forename: Elin
authors.initials: E
authors.lastname: Moe
authors.affiliation: Structural Biology Group, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: Joanna
authors.initials: J
authors.lastname: Timmins
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D034301:Deinococcus / Q000201:enzymology*; D004720:Endonucleases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004720:Endonucleases
keywords: Deinococcus radiodurans; EndoIII-1; EndoIII-3; endonuclease III