Story R M, Weber I T, Steitz T A
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511.
Nature. 1992 Jan 23;355(6358):318-25. doi: 10.1038/355318a0.
The crystal structure of the recA protein from Escherichia coli at 2.3-A resolution reveals a major domain that binds ADP and probably single- and double-stranded DNA. Two smaller subdomains at the N and C termini protrude from the protein and respectively stabilize a 6(1) helical polymer of protein subunits and interpolymer bundles. This polymer structure closely resembles that of recA/DNA filaments determined by electron microscopy. Mutations in recA protein that enhance coprotease, DNA-binding and/or strand-exchange activity can be explained if the interpolymer interactions in the crystal reflect a regulatory mechanism in vivo.
大肠杆菌RecA蛋白2.3埃分辨率的晶体结构揭示了一个结合ADP以及可能结合单链和双链DNA的主要结构域。N端和C端的两个较小亚结构域从蛋白质中突出，分别稳定蛋白质亚基的6(1)螺旋聚合物和聚合物间束。这种聚合物结构与通过电子显微镜确定的RecA/DNA细丝结构非常相似。如果晶体中的聚合物间相互作用反映了体内的一种调节机制，那么RecA蛋白中增强共蛋白酶、DNA结合和/或链交换活性的突变就可以得到解释。
