Seitz E M, Brockman J P, Sandler S J, Clark A J, Kowalczykowski S C
Division of Biological Sciences, Section of Microbiology, University of California, Davis, California 95616-8665 USA.
Genes Dev. 1998 May 1;12(9):1248-53. doi: 10.1101/gad.12.9.1248.
With the discovery that the Saccharomyces cerevisiae Rad51 protein is both structurally and functionally similar to the Escherichia coli RecA protein, the RecA paradigm for homologous recombination was extended to the Eucarya. The ubiquitous presence of RecA and Rad51 protein homologs raises the question of whether this archetypal protein exists within the third domain of life, the Archaea. Here we present the isolation of a Rad51/RecA protein homolog from the archaeon Sulfolobus solfataricus, and show that this protein, RadA, possesses the characteristics of a DNA strand exchange protein: The RadA protein is a DNA-dependent ATPase, forms a nucleoprotein filament on DNA, and catalyzes DNA pairing and strand exchange.
随着酿酒酵母Rad51蛋白在结构和功能上与大肠杆菌RecA蛋白相似这一发现，同源重组的RecA范例扩展到了真核生物。RecA和Rad51蛋白同源物的普遍存在引发了一个问题，即这种原型蛋白是否存在于生命的第三个域——古细菌中。在这里，我们展示了从古细菌嗜热栖热菌中分离出一种Rad51/RecA蛋白同源物，并表明这种蛋白RadA具有DNA链交换蛋白的特征：RadA蛋白是一种依赖DNA的ATP酶，在DNA上形成核蛋白丝，并催化DNA配对和链交换。
