pH- and salt-dependent self-assembly of human Rad51 protein analyzed as fluorescence resonance energy transfer between labeled proteins.
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.
Yoshioka
Ken-ichi
K
FRE2230, Laboratory of Biocatalysis, Centre National de la Recherche Scientifique and Universite de Nantes, F-44322 Nantes cedex 3, France.
Yumoto-Yoshioka
Yoshiko
Y
Fleury
Fabrice
F
Takahashi
Masayuki
M
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*
D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D012235:Rhodamines; D012965:Sodium Chloride; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; D019793:Fluorescein