Goyer C, Altmann M, Trachsel H, Sonenberg N
Department of Biochemistry, McGill University, Montreal, Canada.
J Biol Chem. 1989 May 5;264(13):7603-10.
Photochemical cross-linking of Saccharomyces cerevisiae ribosomal salt wash preparations to cap-labeled mRNA reveals, in addition to the previously characterized 24-kDa cap-binding protein (eIF-4E), the presence of two novel cap-binding proteins (CBPs) of apparent molecular masses of 96 and 150 kDa. Cross-linking of the 96-kDa CBP was found to occur spontaneously without UV light induction. Based on the ATP/Mg2+ requirements, the three CBPs can be subdivided into two classes: 1) ATP/Mg2+ independent (24- and 150 kDa) and 2) Mg2+ dependent (96 kDa). The co-purification of the 24- and 150-kDa CBPs through several different chromatographic steps is consistent with the existence of a yeast CBP complex, possibly analogous to mammalian eIF-4F.
将酿酒酵母核糖体盐洗制剂与帽标记的mRNA进行光化学交联，结果显示，除了先前鉴定的24 kDa帽结合蛋白（eIF - 4E）外，还存在两种新的表观分子量分别为96 kDa和150 kDa的帽结合蛋白（CBP）。发现96 kDa CBP的交联在没有紫外线诱导的情况下自发发生。根据对ATP/Mg2+的需求，这三种CBP可分为两类：1）不依赖ATP/Mg2+（24 kDa和150 kDa）和2）依赖Mg2+（96 kDa）。24 kDa和150 kDa的CBP通过几个不同的色谱步骤共同纯化，这与酵母CBP复合物的存在一致，该复合物可能类似于哺乳动物的eIF - 4F。
