期刊
JOURNAL OF BIOLOGICAL CHEMISTRY
卷 280, 期 49, 页码 40980-40984出版社
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M505896200
关键词
-
资金
- NIGMS NIH HHS [GM50936] Funding Source: Medline
Dmc1 is specifically required for homologous recombination during meiosis. Here we report that the calcium ion enabled Dmc1 from budding yeast to form regular helical filaments on single-stranded-DNA (ssDNA) and activate its strand assimilation activity. Relative to magnesium, calcium increased the affinity of Dmc1 for ATP and but reduces its DNA-dependent ATPase activity. These effects, together with previous studies of other RecA-like recombinases, support the view that ATP binding to Dmc1 protomers is required for functional filament structure. The helical pitch of the Saccharomyces cerevisiae Dmc1- ssDNA helical filament was estimated to be 13.4 +/- 2.5 nm. Analysis of apparently complete Dmc1-ssDNA filaments indicated a stoichiometry of 24 +/- 2 nucleotides per turn of the Dmc1 helix. This finding suggests that the number or protomers per helical turn and/ or the number of nucleotides bound per Dmc1 protomer differs from that reported previously for Rad51 and RecA filaments. Our data support the view that the active form of Dmc1 protein is a helical filament rather than a ring. We speculate that Ca2+ plays a significant role in regulating meiotic recombination.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据