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-3?76) 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, ? = 89.34° and one molecule per asymmetric unit. The EndoIII-3?76 crystals also belonged to the monoclinic space group C2, but with unit-cell parameters a = 91.47, b = 40.53, c = 72.47?Å, ? = 102.53° and one molecule per asymmetric unit. The EndoIII-1 structure was determined by molecular replacement, while the truncated EndoIII-3?76 structure was determined by single-wavelength anomalous dispersion phasing. Refinement of the structures is in progress.

SUBMITTER: Sarre A 

PROVIDER: S-EPMC4259241 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature