Thresher R J, Makhov A M, Hall S D, Kolodner R, Griffith J D
Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill 27599, USA.
J Mol Biol. 1995 Dec 1;254(3):364-71. doi: 10.1006/jmbi.1995.0623.
Electron microscopy has been used to examine Escherichia coli RecT protein alone and in the complexes it forms with DNA substrates, with which it catalyzes strand exchange in vitro. Negative staining has revealed that the 33 kDa RecT protein monomers form open C-shaped and closed O-shaped particles. RecT protein monomers assemble into donut-shaped oligomers containing seven or eight protein monomers and rod-like structures. When bound to single-stranded DNA, RecT forms highly twisted nucleoprotein filaments that are 18 nm in diameter and have a helical pitch of 10 nm. When added to linear duplex DNA in the presence of active RecE protein (exonuclease VIII), filamentous nucleoprotein complexes are formed on the DNA ends and the DNA molecules are frequently cyclized through protein-protein interactions.
电子显微镜已被用于单独检查大肠杆菌RecT蛋白，以及它与DNA底物形成的复合物，它能在体外催化RecT蛋白与DNA底物之间的链交换。负染色显示，33 kDa的RecT蛋白单体形成开放的C形和封闭的O形颗粒。RecT蛋白单体组装成包含七个或八个蛋白单体的甜甜圈状寡聚体和棒状结构。当与单链DNA结合时，RecT形成高度扭曲的核蛋白丝，其直径为18 nm，螺旋间距为10 nm。当在活性RecE蛋白（外切核酸酶VIII）存在的情况下添加到线性双链DNA中时，在DNA末端形成丝状核蛋白复合物，并且DNA分子经常通过蛋白质-蛋白质相互作用环化。
