Park I, Schaeffer E, Sidoli A, Baralle F E, Cohen G N, Zakin M M
Proc Natl Acad Sci U S A. 1985 May;82(10):3149-53. doi: 10.1073/pnas.82.10.3149.
We present the characterization of two overlapping human transferrin genomic clones isolated from a liver DNA library. The two clones represent a total length of 24 kilobase pairs and code for 70% of the protein. The organization of this gene region was elucidated by restriction mapping and DNA sequencing. It contains 12 exons, ranging from 33 to 181 base pairs, separated by introns of 0.7-4.9 kilobase pairs. This gene can be divided into two unequal parts corresponding to the known domains of the protein. Each part is essentially composed of an equal number of exons; introns interrupt the coding sequences, creating homologous exons of similar size in each moiety. Moreover, the pattern of intron interruption of the codon sequence is identical for all the analyzed homologous exon pairs. Comparison with the organization of the ovotransferrin gene shows an identical exon size distribution. These data confirm, at the gene level, the hypothesis that transferrins originated by a gene-duplication event. A model accounting for the origin of the human transferrin gene is presented.
我们展示了从肝脏DNA文库中分离出的两个重叠的人转铁蛋白基因组克隆的特征。这两个克隆的总长度为24千碱基对，编码该蛋白质的70%。通过限制性图谱分析和DNA测序阐明了该基因区域的组织结构。它包含12个外显子，长度从33到181个碱基对不等，被0.7 - 4.9千碱基对的内含子隔开。该基因可分为两个不相等的部分，分别对应于该蛋白质的已知结构域。每个部分基本上由数量相等的外显子组成；内含子打断编码序列，在每个部分中产生大小相似的同源外显子。此外，所有分析的同源外显子对的密码子序列内含子打断模式都是相同的。与卵转铁蛋白基因的组织结构比较显示外显子大小分布相同。这些数据在基因水平上证实了转铁蛋白起源于基因复制事件的假说。本文提出了一个解释人转铁蛋白基因起源的模型。
