Download MendeleyIdentification of fidelity-governing factors in human recombinases DMC1 and RAD51 from cryo-EM structures.
Luo, S.C., Yeh, H.Y., Lan, W.H., Wu, Y.M., Yang, C.H., Chang, H.Y., Su, G.C., Lee, C.Y., Wu, W.J., Li, H.W., Ho, M.C., Chi, P., Tsai, M.D.(2021) Nat Commun 12: 115-115
- PubMed: 33446654
- DOI: https://doi.org/10.1038/s41467-020-20258-1
- Primary Citation of Related Structures:
7C98, 7C99, 7C9A, 7C9C, 7CGY - PubMed Abstract:
Both high-fidelity and mismatch-tolerant recombination, catalyzed by RAD51 and DMC1 recombinases, respectively, are indispensable for genomic integrity. Here, we use cryo-EM, MD simulation and functional analysis to elucidate the structural basis for the mismatch tolerance of DMC1. Structural analysis of DMC1 presynaptic and postsynaptic complexes suggested that the lineage-specific Loop 1 Gln244 (Met243 in RAD51) may help stabilize DNA backbone, whereas Loop 2 Pro274 and Gly275 (Val273/Asp274 in RAD51) may provide an open "triplet gate" for mismatch tolerance. In support, DMC1-Q244M displayed marked increase in DNA dynamics, leading to unobservable DNA map. MD simulation showed highly dispersive mismatched DNA ensemble in RAD51 but well-converged DNA in DMC1 and RAD51-V273P/D274G. Replacing Loop 1 or Loop 2 residues in DMC1 with RAD51 counterparts enhanced DMC1 fidelity, while reciprocal mutations in RAD51 attenuated its fidelity. Our results show that three Loop 1/Loop 2 residues jointly enact contrasting fidelities of DNA recombinases.
Organizational Affiliation:
Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
