Ferré-D'Amaré A R, Prendergast G C, Ziff E B, Burley S K
Laboratories of Molecular Biophysics, Rockefeller University, New York, New York 10021.
Nature. 1993 May 6;363(6424):38-45. doi: 10.1038/363038a0.
The three-dimensional structure of the basic/helix-loop-helix/leucine zipper domain of the transcription factor Max complexed with DNA has been determined by X-ray crystallography at 2.9 A resolution. Max binds as a dimer to its recognition sequence CACGTG by direct contacts between the alpha-helical basic region and the major groove. This symmetric homodimer, a new protein fold, is a parallel, left-handed, four-helix bundle, with each monomer containing two alpha-helical segments separated by a loop. The two alpha-helical segments are composed of the basic region plus helix 1 and helix 2 plus the leucine repeat, respectively. As in GCN4, the leucine repeat forms a parallel coiled coil.
转录因子Max与DNA复合的碱性/螺旋-环-螺旋/亮氨酸拉链结构域的三维结构已通过X射线晶体学在2.9埃分辨率下确定。Max以二聚体形式通过α-螺旋碱性区域与大沟之间的直接接触结合到其识别序列CACGTG上。这种对称的同型二聚体是一种新的蛋白质折叠形式，是一个平行的、左手的四螺旋束，每个单体包含由一个环隔开的两个α-螺旋段。这两个α-螺旋段分别由碱性区域加螺旋1和螺旋2加亮氨酸重复序列组成。与GCN4一样，亮氨酸重复序列形成一个平行的卷曲螺旋。
