Milton D L, Casper M L, Wills N M, Gesteland R F
Howard Hughes Medical Institute Laboratory, Department of Human Genetics, University of Utah, Salt Lake City 84132.
Nucleic Acids Res. 1990 Feb 25;18(4):817-20. doi: 10.1093/nar/18.4.817.
Synthetic DNA fragments were constructed to determine the effect of G tracts, in conjunction with periodically spaced A tracts, on DNA bends. Relative length measurements showed that the G tracts spaced at the half helical turn enhanced the DNA bend. When the G tract was interrupted with a thymine or shortened to one or two guanines, the relative lengths decreased. If the G tract was replaced with either an A tract or a T tract, the bend was cancelled. Replacement with a C tract decreased the relative length to that of a thymine interruption suggesting that bend enhancement due to G tracts requires A tracts on the same strand.
构建合成DNA片段以确定G序列与周期性间隔的A序列一起对DNA弯曲的影响。相对长度测量表明，以半螺旋间距排列的G序列增强了DNA弯曲。当G序列被一个胸腺嘧啶打断或缩短为一两个鸟嘌呤时，相对长度减小。如果G序列被A序列或T序列取代，弯曲就会消失。被C序列取代会使相对长度降低到胸腺嘧啶打断时的水平，这表明G序列导致的弯曲增强需要同一条链上有A序列。
