Flanagan J G, Lefranc M P, Rabbitts T H
Cell. 1984 Mar;36(3):681-8. doi: 10.1016/0092-8674(84)90348-9.
Nucleotide sequences of the human alpha 1 and two allelic alpha 2 immunoglobulin heavy chain constant region genes are presented. The genes contain three exons, each encoding a single constant region protein domain. The protein hinge region is encoded at the 5' end of the second exon, and the rapid evolutionary changes in length of the hinge correspond to duplications or deletions within the hinge-coding region, probably facilitated by repeats in the DNA sequence. Alignment of the alpha 1 and alpha 2 gene sequences reveals an unusual coupled deletion-duplication in the 5'-flanking region, which can be explained in terms of a slipped-strand mispairing model. Comparison of nucleotide sequences of the alpha 1 gene and two alleles of the alpha 2 gene indicates a localized transfer of genetic information from the 3' end of the alpha 1 gene to one of the alpha 2 alleles, probably by a gene conversion. At one end of the region within which conversion apparently occurred, there is a 40 bp sequence of the type that can form Z-DNA.
本文展示了人类α1和两个等位基因α2免疫球蛋白重链恒定区基因的核苷酸序列。这些基因包含三个外显子，每个外显子编码一个恒定区蛋白结构域。蛋白质铰链区在第二个外显子的5'端编码，铰链长度的快速进化变化对应于铰链编码区内的重复或缺失，这可能是由DNA序列中的重复所促进的。α1和α2基因序列的比对揭示了5'侧翼区域存在异常的耦合缺失-重复现象，这可以用滑链错配模型来解释。α1基因与α2基因的两个等位基因的核苷酸序列比较表明，遗传信息可能通过基因转换从α1基因的3'端局部转移到了其中一个α2等位基因。在明显发生转换的区域的一端，有一段40 bp的可形成Z-DNA的序列类型。
