Kessler M M, Zhao J, Moore C L
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111-1800, USA.
J Biol Chem. 1996 Oct 25;271(43):27167-75. doi: 10.1074/jbc.271.43.27167.
The cleavage/polyadenylation factor I (CF I) is one of four factors required for mRNA 3' end formation in the yeast Saccharomyces cerevisiae. Here we describe the purification of CF I and its separation into two components, CF IA and CF IB. Both components are needed to reconstitute CF I activity in cleavage and poly(A) addition. CF IA consists of a complex of four polypeptides of 76, 70, 50, and 38 kDa, and CF IB is a single 73-kDa polypeptide. The 76- and 38-kDa subunits of CF IA correspond to the previously identified RNA14 and RNA15 proteins. The RNA14 protein, but not the 70- or 50-kDa proteins, coimmunoprecipitates with the RNA15 protein, indicating that RNA14 and RNA15 proteins exist in a tight complex. RNA15 is the only subunit of CF I that can be cross-linked to pre-mRNA.
切割/聚腺苷酸化因子I（CF I）是酿酒酵母中mRNA 3'末端形成所需的四种因子之一。在此，我们描述了CF I的纯化及其分离为两个组分，CF IA和CF IB。在切割和聚腺苷酸化过程中，重构CF I活性需要这两个组分。CF IA由76、70、50和38 kDa的四种多肽组成的复合物，CF IB是一条73 kDa的单一多肽。CF IA的76 kDa和38 kDa亚基分别对应于先前鉴定的RNA14和RNA15蛋白。RNA14蛋白，而非70 kDa或50 kDa蛋白，与RNA15蛋白共免疫沉淀，表明RNA14和RNA15蛋白存在于紧密复合物中。RNA15是CF I中唯一能与前体mRNA交联的亚基。
