Defining the influence of Rad51 and Dmc1 lineage-specific amino acids on genetic recombination.
Genes Dev
; 33(17-18): 1191-1207, 2019 09 01.
Article
em En
| MEDLINE
| ID: mdl-31371435
ABSTRACT
The vast majority of eukaryotes possess two DNA recombinases Rad51, which is ubiquitously expressed, and Dmc1, which is meiosis-specific. The evolutionary origins of this two-recombinase system remain poorly understood. Interestingly, Dmc1 can stabilize mismatch-containing base triplets, whereas Rad51 cannot. Here, we demonstrate that this difference can be attributed to three amino acids conserved only within the Dmc1 lineage of the Rad51/RecA family. Chimeric Rad51 mutants harboring Dmc1-specific amino acids gain the ability to stabilize heteroduplex DNA joints with mismatch-containing base triplets, whereas Dmc1 mutants with Rad51-specific amino acids lose this ability. Remarkably, RAD-51 from Caenorhabditis elegans, an organism without Dmc1, has acquired "Dmc1-like" amino acids. Chimeric C. elegans RAD-51 harboring "canonical" Rad51 amino acids gives rise to toxic recombination intermediates, which must be actively dismantled to permit normal meiotic progression. We propose that Dmc1 lineage-specific amino acids involved in the stabilization of heteroduplex DNA joints with mismatch-containing base triplets may contribute to normal meiotic recombination.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Recombinação Genética
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Recombinases
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Rad51 Recombinase
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Aminoácidos
Limite:
Animals
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article