Sachs A B, Bond M W, Kornberg R D
Cell. 1986 Jun 20;45(6):827-35. doi: 10.1016/0092-8674(86)90557-x.
Nuclear and cytoplasmic poly(A)-binding proteins have been purified from Saccharomyces cerevisiae, and antisera have been used to isolate a gene that encodes them. The gene occurs in a single copy on chromosome 5 and gives rise to a unique, unspliced 2.1 kb transcript. The nuclear protein appears to be derived from the cytoplasmic one by proteolytic cleavage into 53 and 17 kd polypeptides that remain associated during isolation. DNA sequence determination reveals four tandemly arrayed 90 amino acid regions of homology that probably represent poly(A)-binding domains. A 55 residue A-rich region upstream of the initiator methionine codon in the mRNA shows an affinity for poly(A)-binding protein comparable to that of poly(A)180-220, raising the possibility of feedback regulation of translation.
已从酿酒酵母中纯化出核和细胞质聚腺苷酸结合蛋白，并使用抗血清分离出编码它们的基因。该基因在5号染色体上以单拷贝形式存在，并产生一个独特的、未剪接的2.1 kb转录本。核蛋白似乎是通过蛋白水解切割从细胞质蛋白衍生而来，形成53 kd和17 kd的多肽，在分离过程中它们保持结合状态。DNA序列测定揭示了四个串联排列的90个氨基酸的同源区域，可能代表聚腺苷酸结合结构域。mRNA中起始甲硫氨酸密码子上游55个残基的富含A区域对聚腺苷酸结合蛋白的亲和力与聚腺苷酸180 - 220相当，这增加了翻译反馈调节的可能性。
