title: pH- and salt-dependent self-assembly of human Rad51 protein analyzed as fluorescence resonance energy transfer between labeled proteins.
abstract: Human HsRad51 protein assembles on a DNA molecule through cooperative binding and forms a long filament for homologous recombination. We have characterized the self-assembly of HsRad51 by measuring the fluorescence resonance energy transfer from the fluorescein-labeled protein to the rhodamine-labeled protein. Self-assembly quickly reached equilibrium and can be described by the head-to-tail polymerization of monomers, like that of its procaryotic homologue, RecA. It depended strongly on pH and was inhibited by high salt concentrations, indicating that ionic interactions between negatively and positively charged aminoacid residues are important. By contrast, neither ATP nor ADP significantly affected the reaction.
authors.affiliation: FRE2230, Laboratory of Biocatalysis, Centre National de la Recherche Scientifique and Universite de Nantes, F-44322 Nantes cedex 3, France.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yoshioka
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yumoto-Yoshioka
authors.forename: Fabrice
authors.initials: F
authors.lastname: Fleury
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D019793:Fluorescein / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D051135:Rad51 Recombinase; D011994:Recombinant Proteins / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D012235:Rhodamines; D012965:Sodium Chloride; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; D019793:Fluorescein