Characterization of the recombination activities of the Entamoeba histolytica Rad51 recombinase.
Mol Biochem Parasitol
; 210(1-2): 71-84, 2016.
Article
en En
| MEDLINE
| ID: mdl-27678398
ABSTRACT
The protozoan parasite responsible for human amoebiasis is Entamoeba histolytica. An important facet of the life cycle of E. histolytica involves the conversion of the mature trophozoite to a cyst. This transition is thought to involve homologous recombination (HR), which is dependent upon the Rad51 recombinase. Here, a biochemical characterization of highly purified ehRad51 protein is presented. The ehRad51 protein preferentially binds ssDNA, forms a presynaptic filament and possesses ATP hydrolysis activity that is stimulated by the presence of DNA. Evidence is provided that ehRad51 catalyzes robust DNA strand exchange over at least 5.4 kilobase pairs. Although the homologous DNA pairing activity of ehRad51 is weak, it is strongly enhanced by the presence of two HR accessory cofactors, calcium and Hop2-Mnd1. The biochemical system described herein was used to demonstrate the potential for targeting ehRad51 with two small molecule inhibitors of human RAD51. We show that 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) inhibited ehRad51 by interfering with DNA binding and attenuated encystation in Entamoeba invadens, while B02 had no effect on ehRad51 strand exchange activity. These results provide insight into the underlying mechanism of homology-directed DNA repair in E. histolytica.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Protozoarias
/
Entamoeba histolytica
/
Recombinasa Rad51
/
Recombinación Homóloga
Idioma:
En
Revista:
Mol Biochem Parasitol
Año:
2016
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS