title: Homologous pairing and ring and filament structure formation activities of the human Xrcc2*Rad51D complex.
abstract: The Xrcc2 and Rad51D/Rad51L3 proteins, which belong to the Rad51 paralogs, are required for homologous recombinational repair (HRR) in vertebrates. The Xrcc2 and Rad51D/Rad51L3 genes, whose products interact with each other, have essential roles in ensuring normal embryonic development. In the present study, we coexpressed the human Xrcc2 and Rad51D/Rad51L3 proteins (Xrcc2 and Rad51D, respectively) in Escherichia coli, and purified the Xrcc2*Rad51D complex to homogeneity. The Xrcc2 small middle dotRad51D complex catalyzed homologous pairing between single-stranded and double-stranded DNA, similar to the function of the Xrcc3*Rad51C complex, which is another complex of the Rad51 paralogs. An electron microscopic analysis showed that Xrcc2*Rad51D formed a multimeric ring structure in the absence of DNA. In the presence of ssDNA, Xrcc2*Rad51D formed a filamentous structure, which is commonly observed among the human homologous pairing proteins, Rad51, Rad52, and Xrcc3*Rad51C.
authors.affiliation: RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kurumizaka
authors.forename: Shukuko
authors.initials: S
authors.lastname: Ikawa
authors.forename: Maki
authors.initials: M
authors.lastname: Nakada
authors.forename: Rima
authors.initials: R
authors.lastname: Enomoto
authors.forename: Wataru
authors.initials: W
authors.lastname: Kagawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Kinebuchi
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Yamazoe
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Takehiko
authors.initials: T
authors.lastname: Shibata
mesh_terms: D002384:Catalysis; D002942:Circular Dichroism; D002945:Cisplatin / Q000494:pharmacology*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D009698:Nucleoproteins / Q000378:metabolism; D011485:Protein Binding
chemical_list: D003432:Cross-Linking Reagents; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D009698:Nucleoproteins; C112629:RAD51D protein, human; C113187:XRCC2 protein, human; D004247:DNA; D002945:Cisplatin