Format

Send to

Choose Destination
J Biol Chem. 2018 Mar 16;293(11):4191-4200. doi: 10.1074/jbc.RA117.001143. Epub 2018 Jan 30.

Spontaneous self-segregation of Rad51 and Dmc1 DNA recombinases within mixed recombinase filaments.

Author information

1
From the Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, 10032.
2
Department of Genetics and Development, Columbia University, New York, New York, 10032, and.
3
Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, 06520.
4
From the Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, 10032, ecg2108@cumc.columbia.edu.

Abstract

During meiosis, the two DNA recombinases Rad51 and Dmc1 form specialized presynaptic filaments that are adapted for performing recombination between homologous chromosomes. There is currently a limited understanding of how these two recombinases are organized within the meiotic presynaptic filament. Here, we used single molecule imaging to examine the properties of presynaptic complexes composed of both Rad51 and Dmc1. We demonstrate that Rad51 and Dmc1 have an intrinsic ability to self-segregate, even in the absence of any other recombination accessory proteins. Moreover, we found that the presence of Dmc1 stabilizes the adjacent Rad51 filaments, suggesting that cross-talk between these two recombinases may affect their biochemical properties. Based upon these findings, we describe a model for the organization of Rad51 and Dmc1 within the meiotic presynaptic complex, which is also consistent with in vivo observations, genetic findings, and biochemical expectations. This model argues against the existence of extensively intermixed filaments, and we propose that Rad51 and Dmc1 have intrinsic capacities to form spatially distinct filaments, suggesting that additional recombination cofactors are not required to segregate the Rad51 and Dmc1 filaments.

KEYWORDS:

DNA binding protein; DNA curtains; DNA recombination; DNA repair; Dmc1; Rad51; homologous recombination; meiosis; presynaptic complex; presynaptic filament; single molecule; single-molecule biophysics

PMID:
29382724
PMCID:
PMC5858004
DOI:
10.1074/jbc.RA117.001143

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center