Open AccessExpression, purification and crystallization of Swi5 and the Swi5–Sfr1 complex from fission yeast
Author(s) -
Kuwabara Naoyuki,
Hashimoto Hiroshi,
Yamada Noriyo,
Unzai Satoru,
Ikeguchi Mitsunori,
Sato Mamoru,
Murayama Yasuto,
Iwasaki Hiroshi,
Shimizu Toshiyuki
Publication year - 2010
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309110032239
Subject(s) - crystallography , protein filament , tetramer , chemistry , biochemistry , enzyme
The assembly of the presynaptic filament of recombinases represents the most important step in homologous recombination. The formation of the filament requires assistance from mediator proteins. Swi5 and Sfr1 have been identified as mediators in fission yeast and these proteins form a complex that stimulates strand exchange. Here, the expression, purification and crystallization of Swi5 and its complex with an N‐terminally truncated form of Sfr1 (ΔN180Sfr1) are presented. Analytical ultracentrifugation of the purified samples showed that Swi5 and the protein complex exist as tetramers and heterodimers in solution, respectively. Swi5 was crystallized in two forms belonging to space groups C 2 and R 3 and the crystals diffracted to 2.7 Å resolution. Swi5–ΔN180Sfr1 was crystallized in space group P 2 1 2 1 2 and the crystals diffracted to 2.3 Å resolution. The crystals of Swi5 and Swi5–ΔN180Sfr1 are likely to contain one tetramer and two heterodimers in the asymmetric unit, respectively.