Nucleotide Cofactor-Dependent Structural Change of Xenopus laevis Rad51 Protein Filament Detected by Small-Angle Neutron Scattering Measurements in Solution

详细信息    查看全文

• 作者：Christine Ellouze ; Hye-Kyung Kim ; Kazuhiro Maeshima ; Eimer Tuite ; Katsumi Morimatsu ; Toshihiro Horii ; Kell Mortensen ; Bengt Nordé ; n ; and Masayuki Takahashi
• 刊名：Biochemistry
• 出版年：1997
• 出版时间：November 4, 1997
• 年：1997
• 卷：36
• 期：44
• 页码：13524 - 13529
• 全文大小：123K
• 年卷期：v.36,no.44(November 4, 1997)
• ISSN：1520-4995

文摘

Rad51 protein, a eukaryotic homologue of RecA protein, forms afilamentous complex withDNA and catalyzes homologous recombination. We have analyzed thestructure of Xenopus Rad51 protein(XRad51.1) in solution by small-angle neutron scattering (SANS).The measurements showed thatXRad51.1 forms a helical filament independently of DNA. The sizesof the cross-sectional and helicalpitch of the filament could be determined, respectively, from a Guinierplot and the position of the subsidiarymaximum of SANS data. We observed that the helical structure ismodified by nucleotide binding as inthe case of RecA. Upon ATP binding under high-salt conditions (600mM NaCl), the helical pitch ofXRad51.1 filament was increased from 8 to 10 nm and the cross-sectionaldiameter decreased from 7 to6 nm. The pitch sizes of XRad51.1 are similar to, though slightlylarger than, those of RecA filamentunder corresponding conditions. A similar helical pitch size wasobserved by electron microscopy forbudding yeast Rad51 [Ogawa, T., et al. (1993) Science 259,1896-1899]. In contrast to the RecA filament,the structure of XRad51.1 filament with ADP is not significantlydifferent from that with ATP. Thus,the hydrolysis of ATP to ADP does not modify the helical filament ofXRad51.1. Together with ourrecent observation that ADP does not weaken the XRad51.1/DNAinteraction, the effect of ATP hydrolysison XRad51.1 nucleofilament should be very different from that onRecA.