Sonenberg N
Nucleic Acids Res. 1981 Apr 10;9(7):1643-56. doi: 10.1093/nar/9.7.1643.
Two proteins of apparent molecular weights of 28,000 and 50,000 daltons were shown to recognize and cross-link specifically to the 5' cap end of oxidized reovirus mRNA. Cross-linking of these proteins to mRNA was ATP/Mg++ dependent, in sharp contrast to cross-linking of a 24K cap binding protein which was purified and characterized previously (Sonenberg, N., Rupprecht, K.M., Hecht, S.M. and Shatkin, A.J. (1979) Proc. Natl. Acad. Sci, USA 76, 4345-4349). Non-hydrolyzable analogues of ATP as well as other nucleotides did not substitute for ATP in the cross-linking reaction and Mg++ was significantly preferred over other divalent cations in cross-linking of the 28K and 50K dalton proteins. A model involving the function of the latter proteins in recognition and unwinding of the 5' end structure of capped eukaryotic mRNAs is suggested.
研究表明，两种表观分子量分别为28,000和50,000道尔顿的蛋白质能够特异性识别氧化呼肠孤病毒mRNA的5'帽端并与之交联。这些蛋白质与mRNA的交联依赖于ATP/Mg++，这与之前纯化和鉴定的一种24K帽结合蛋白的交联情况形成鲜明对比（索嫩贝格，N.，鲁普雷希特，K.M.，赫希特，S.M.和沙金，A.J.（1979年）《美国国家科学院院刊》76，4345 - 4349）。ATP的不可水解类似物以及其他核苷酸在交联反应中不能替代ATP，并且在28K和50K道尔顿蛋白质的交联过程中，Mg++明显优于其他二价阳离子。有人提出了一个模型，该模型涉及后一种蛋白质在识别和解开加帽真核mRNA的5'端结构中的作用。
