Koczan D, Hobom G, Seyfert H M
Institut für Mikrobiologie und Molekularbiolgie Justus-Liebig-Universität Giessen, FRG.
Nucleic Acids Res. 1991 Oct 25;19(20):5591-6. doi: 10.1093/nar/19.20.5591.
We report the sequence of the complete bovine alpha-s1 casein gene eludicating for the first time the genomic organization of an alpha-s type casein gene. Extending over 17508 bp the gene is split into 19 exons, ranging in size from 24 bp to 385 bp. Except for the translational stop codon not a single coding triplet of the alpha-s1 reading frame is disrupted by any of the splice junctions, which all confirm to known splice consensus sequences. Nine out of 16 coding exons begin with a 'GAX' codon, specific for glutamate. Splicing of this codon from exon 10 to the preceding exon creates a major phosphorylation site. An intron-exon-intron stretch of 154 bp comprising exons 10 and 13 is found precisely duplicated. Associated with the gene, copies of 8 atriodactyla retroposons are found, 6 of which are interspersed into the sequences of the three longest introns. We discuss the possibility that three functional parts of the gene have been recruited and evolutionary conserved at a time before gene diversification gave rise to the separate evolution of alpha- and beta-type casein-genes.
我们报道了完整的牛α-s1酪蛋白基因序列，首次阐明了α-s型酪蛋白基因的基因组结构。该基因全长17508 bp，被分割为19个外显子，大小从24 bp到385 bp不等。除了翻译终止密码子外，α-s1阅读框的任何编码三联体都未被任何剪接连接破坏，所有这些剪接连接均符合已知的剪接共有序列。16个编码外显子中有9个以“GAX”密码子开始，该密码子对谷氨酸具有特异性。从外显子10到前一个外显子对该密码子进行剪接会产生一个主要的磷酸化位点。发现一个由外显子10和13组成的154 bp的内含子-外显子-内含子片段被精确复制。与该基因相关，发现了8个偶蹄目反转录转座子的拷贝，其中6个散布在三个最长内含子的序列中。我们讨论了该基因的三个功能部分在基因多样化导致α-和β-型酪蛋白基因单独进化之前就已被招募并在进化过程中保守的可能性。
