Structure of the human DNA-repair protein RAD52 containing surface mutations

The Rad52 protein is a eukaryotic single-strand DNA-annealing protein that is involved in the homologous recombinational repair of DNA double-strand breaks. The isolated N-terminal half of the human RAD52 protein (RAD521–212) forms an undecameric ring structure with a surface that is mostly positively charged. In the present study, it was found that RAD521–212 containing alanine mutations of the charged surface residues (Lys102, Lys133 and Glu202) is highly amenable to crystallization. The structure of the mutant RAD521–212 was solved at 2.4 Å resolution. The structure revealed an association between the symmetry-related RAD521–212 rings, in which a partially unfolded, C-terminal region of RAD52 extended into the DNA-binding groove of the neighbouring ring in the crystal. The alanine mutations probably reduced the surface entropy of the RAD521–212 ring and stabilized the ring–ring association observed in the crystal.
Source: Acta Crystallographica Section F - Category: Biochemistry Authors: Tags: ssDNA-binding protein single-strand annealing proteins homologous recombinational repair surface-entropy reduction higher order interaction RAD52 research communications Source Type: research