The redefined DNA-binding domain of human xeroderma pigmentosum complementation group A: production, crystallization and structure solution

Human xeroderma pigmentosum complementation group A (XPA) is a scaffold protein that plays significant roles in DNA-damage verification and in recruiting downstream endonucleases to facilitate the repair of DNA lesions in nucleotide-excision repair. XPA98 – 219 (residues 98 – 219) has been identified as a DNA-binding domain and has been extensively studied in the last two decades. However, the most recent studies have redefined the DNA-binding domain as XPA98 – 239 (residues 98 – 239); it exerts a remarkably higher DNA-binding affinity than XPA98 – 219 and has a binding affinity that is quite similar to that of the full-length protein. Here, the production, crystallization and structure solution of human XPA98 – 239 are described. Crystals were obtained using a precipitant composed of 1.8   M ammonium citrate tribasic pH 7.0. Native X-ray diffraction data and zinc single-wavelength anomalous diffraction (SAD) data were collected to 1.93 and 2.06   Å resolution, respectively. The crystals belonged to space group P3, with unit-cell parameters a = 67.1, b = 67.1, c = 35.6   Å , γ   =   120.0 ° . Crystal-content analysis showed the presence of one molecule in the asymmetric unit, corresponding to a Matthews coefficient of 2.65   Å 3   Da − 1 and a solvent content of 53.6%. The initial phases were solved and the structure model was automatically built by zinc SAD using the AutoSol program. The initial structure model covered 119 of 142 residues in th...
Source: Acta Crystallographica Section F - Category: Biochemistry Authors: Tags: XPA DNA-binding domain nucleotide-excision repair research communications Source Type: research