Marcotrigiano J, Gingras A C, Sonenberg N, Burley S K
Laboratories of Molecular Biophysics, The Rockefeller University, New York, New York 10021, USA.
Cell. 1997 Jun 13;89(6):951-61. doi: 10.1016/s0092-8674(00)80280-9.
The X-ray structure of the eukaryotic translation initiation factor 4E (eIF4E), bound to 7-methyl-GDP, has been determined at 2.2 A resolution. eIF4E recognizes 5' 7-methyl-G(5')ppp(5')N mRNA caps during the rate-limiting initiation step of translation. The protein resembles a cupped hand and consists of a curved, 8-stranded antiparallel beta sheet, backed by three long alpha helices. 7-methyl-GDP binds in a narrow cap-binding slot on the molecule's concave surface, where 7-methyl-guanine recognition is mediated by base sandwiching between two conserved tryptophans, plus formation of three hydrogen bonds and a van der Waals contact between its N7-methyl group and a third conserved tryptophan. The convex dorsal surface of the molecule displays a phylogenetically conserved hydrophobic/acidic portion, which may interact with other translation initiation factors and regulatory proteins.
真核生物翻译起始因子4E（eIF4E）与7-甲基-GDP结合的X射线结构已在2.2埃分辨率下确定。在翻译的限速起始步骤中，eIF4E识别5' 7-甲基-G(5')ppp(5')N mRNA帽结构。该蛋白质形似一个捧着东西的手，由一个弯曲的8股反平行β折叠片组成，后面有三个长α螺旋。7-甲基-GDP结合在分子凹面上一个狭窄的帽结合槽中，其中7-甲基鸟嘌呤的识别是通过夹在两个保守色氨酸之间的碱基夹层，以及其N7-甲基基团与第三个保守色氨酸之间形成三个氢键和一个范德华接触来介导的。分子的凸背表面显示出一个系统发育上保守的疏水/酸性部分，它可能与其他翻译起始因子和调节蛋白相互作用。
