Rupert P B, Daughdrill G W, Bowerman B, Matthews B W
Institute of Molecular Biology, Department of Chemistry, University of Oregon, Eugene 97403, USA.
Nat Struct Biol. 1998 Jun;5(6):484-91. doi: 10.1038/nsb0698-484.
The DNA-binding domain of Skn-1, a developmental transcription factor that specifies mesoderm in C. elegans, is shown by X-ray crystallography to have a novel fold in which a compact, monomeric, four-helix unit organizes two DNA-contact elements. At the C-terminus, a helix extends from the domain to occupy the major groove of DNA in a manner similar to bZip proteins. Skn-1, however, lacks the leucine zipper found in all bZips. Additional contacts with the DNA are made by a short basic segment at the N-terminus of the domain, reminiscent of the 'homeodomain arm'.
Skn-1是一种在秀丽隐杆线虫中决定中胚层命运的发育转录因子，其DNA结合结构域经X射线晶体学研究显示具有一种新颖的折叠方式，即一个紧密的单体四螺旋单元构成了两个DNA接触元件。在C端，一条螺旋从该结构域延伸出来，以类似于bZip蛋白的方式占据DNA的大沟。然而，Skn-1缺乏所有bZip蛋白中都存在的亮氨酸拉链结构。该结构域N端的一个短碱性片段与DNA形成了额外的接触，这让人联想到“同源结构域臂”。
