Bipartite stimulatory action of the Hop2-Mnd1 complex on the Rad51 recombinase

Genes Dev. 2007 Jul 15;21(14):1747-57. doi: 10.1101/gad.1563007.

Abstract

The HOP2 and MND1 genes are indispensable for meiotic recombination. The products of these genes associate to form a stable heterodimeric complex that binds DNA and stimulates the recombinase activity of Rad51 and Dmc1. Here we conduct molecular studies to delineate the action mechanism of the Hop2-Mnd1 complex. We present evidence to implicate Hop2 as the major DNA-binding subunit and Mnd1 as the prominent Rad51 interaction entity. Hop2-Mnd1 stabilizes the Rad51-single-stranded DNA (ssDNA) nucleoprotein filament, the catalytic intermediate in recombination reactions. We also show that Hop2-Mnd1 enhances the ability of the Rad51-ssDNA nucleoprotein filament to capture duplex DNA, an obligatory step in the formation of the synaptic complex critical for DNA joint formation. Thus, our results unveil a bipartite mechanism of Hop2-Mnd1 in homologous DNA pairing: stabilization of the Rad51 presynaptic filament and duplex DNA capture to enhance synaptic complex formation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromosomal Proteins, Non-Histone / chemistry
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Chromosome Pairing
  • DNA, Single-Stranded / chemistry
  • DNA, Single-Stranded / metabolism
  • Humans
  • In Vitro Techniques
  • Meiosis
  • Mice
  • Models, Biological
  • Multiprotein Complexes
  • Rad51 Recombinase / chemistry
  • Rad51 Recombinase / genetics
  • Rad51 Recombinase / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Recombination, Genetic
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • Chromosomal Proteins, Non-Histone
  • DNA, Single-Stranded
  • HOP2 protein, S cerevisiae
  • MND1 protein, S cerevisiae
  • Multiprotein Complexes
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • RAD51 protein, human
  • Rad51 Recombinase