Mechanistic insights into the role of Hop2-Mnd1 in meiotic homologous DNA pairing
Journal
Nucleic Acids Research
Journal Volume
42
Journal Issue
2
Pages
906 - 917
Date Issued
2014
Author(s)
Zhao, Weixing
Saro, Dorina
Hammel, Michal
Kwon, Youngho
Xu, Yuanyuan
Rambo, Robert P.
Williams, Gareth J.
Lu, Lucy
Pezza, Roberto J.
Camerini-Otero, R. Daniel
Tainer, John A.
Wang, Hong-Wei
Sung, Patrick
Abstract
The Hop2-Mnd1 complex functions with the DMC1 recombinase in meiotic recombination. Hop2-Mnd1 stabilizes the DMC1-single-stranded DNA (ssDNA) filament and promotes the capture of the double-stranded DNA partner by the recombinase filament to assemble the synaptic complex. Herein, we define the action mechanism of Hop2-Mnd1 in DMC1-mediated recombination. Small angle X-ray scattering analysis and electron microscopy reveal that the heterodimeric Hop2-Mnd1 is a V-shaped molecule. We show that the protein complex harbors three distinct DNA binding sites, and determine their functional relevance. Specifically, the N-terminal double-stranded DNA binding functions of Hop2 and Mnd1 co-operate to mediate synaptic complex assembly, whereas ssDNA binding by the Hop2 C-terminus helps stabilize the DMC1-ssDNA filament. A model of the Hop2-Mnd1-DMC1-ssDNA ensemble is proposed to explain how it mediates homologous DNA pairing in meiotic recombination. © 2013 The Author(s).
Type
journal article