Donaldson L W, Petersen J M, Graves B J, McIntosh L P
Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada.
Biochemistry. 1994 Nov 22;33(46):13509-16. doi: 10.1021/bi00250a001.
The members of the ets gene family of transcription factors are characterized by a conserved 85-residue DNA-binding region, termed the ETS domain, that lacks sequence homology to structurally characterized DNA-binding motifs. The secondary structure of the ETS domain of murine Ets-1 was determined on the basis of NMR chemical shifts, NOE and J-coupling constraints, amide hydrogen exchange, circular dichroism, and FT-IR spectroscopy. The ETS domain is composed of three alpha-helices (H) and four beta-strands (S) arranged in the order H1-S1-S2-H2-H3-S3-S4. The four-stranded antiparallel beta-sheet is the scaffold for a putative helix-turn-helix DNA recognition motif formed by helices 2 and 3. The 25 residues extending beyond the ETS domain to the native C-terminus of the truncated Ets-1 also contain a helical segment. On the basis of the similarity of this topology with that of catabolite activator protein (CAP), heat shock factor (HSF), and hepatocyte nuclear factor (HNF-3 gamma), we propose that ets proteins are members of the superfamily of winged helix-turn-helix DNA-binding proteins.
转录因子ets基因家族的成员具有一个保守的含85个氨基酸残基的DNA结合区域，称为ETS结构域，该区域与结构已明确的DNA结合基序缺乏序列同源性。基于核磁共振化学位移、核Overhauser效应（NOE）和J耦合限制、酰胺氢交换、圆二色性以及傅里叶变换红外光谱，确定了小鼠Ets-1的ETS结构域的二级结构。ETS结构域由三个α螺旋（H）和四条β链（S）组成，排列顺序为H1-S1-S2-H2-H3-S3-S4。四条反平行的β折叠片层是由螺旋2和螺旋3形成的假定螺旋-转角-螺旋DNA识别基序的支架。从截短的Ets-1的ETS结构域延伸至天然C末端的25个残基也包含一个螺旋片段。基于这种拓扑结构与分解代谢物激活蛋白（CAP）、热休克因子（HSF）和肝细胞核因子（HNF-3γ）的拓扑结构的相似性，我们提出ets蛋白是有翼螺旋-转角-螺旋DNA结合蛋白超家族的成员。
