Creighton T E, Charles I G
J Mol Biol. 1987 Mar 5;194(1):11-22. doi: 10.1016/0022-2836(87)90711-x.
The genes for bovine pancreatic trypsin inhibitor and a homologous protease inhibitor have been characterized using messenger RNA, clones of complementary DNA copies and genomic fragments. Both genes consist of three exons and two introns and are virtually identical in sequence, suggesting that recently they either arose by gene duplication or were subject to gene conversion. However, they differ markedly in their promoter regions and in a segment within the first intron. Perhaps as a consequence, the two genes can be expressed using different transcription start sites, and the two proteins are found in different bovine tissues. Each middle exon encodes primarily the mature protein, while the other two exons define amino- and carboxyl-terminal extensions of 33 or 35 and 7 amino acid residues, respectively. The amino-terminal extensions contain a signal peptide-like sequence, suggesting that the proteins are destined for cellular compartments. The remaining extensions at both ends may be involved in targetting of the proteins, and there are some similarities to other proteins destined for cellular compartments.
已利用信使核糖核酸、互补脱氧核糖核酸拷贝克隆和基因组片段对牛胰蛋白酶抑制剂基因及一种同源蛋白酶抑制剂基因进行了表征。这两个基因均由三个外显子和两个内含子组成，序列几乎相同，这表明它们要么是最近通过基因复制产生的，要么经历了基因转换。然而，它们在启动子区域以及第一个内含子内的一个片段上存在显著差异。或许正因如此，这两个基因可以使用不同的转录起始位点进行表达，并且在不同的牛组织中发现了这两种蛋白质。每个中间外显子主要编码成熟蛋白，而另外两个外显子分别定义了33个或35个氨基酸残基的氨基末端延伸和7个氨基酸残基的羧基末端延伸。氨基末端延伸包含一个类似信号肽的序列，这表明这些蛋白质注定要进入细胞区室。两端其余的延伸部分可能参与蛋白质的靶向定位，并且与其他注定要进入细胞区室的蛋白质存在一些相似之处。
