Suzuki T, Johnston P N, Board P G
Molecular Genetics Group, John Curtin School of Medical Research, Australian National University, Canberra.
Genomics. 1993 Dec;18(3):680-6. doi: 10.1016/s0888-7543(05)80373-8.
We have isolated and characterized genomic DNA encoding several human Alpha class glutathione S-transferase genes and pseudogenes. All the genes are composed of seven exons with boundaries identical to those of the Alpha class genes in rats. The GSTA1 gene is approximately 12 kb in length and is closely flanked by other Alpha class gene sequences. The complete sequence of the 1.7-kb intergenic region between exon 7 of an upstream pseudogene and exon 1 of the GSTA1 gene has been determined. An additional gene that encodes an uncharacterized Alpha class glutathione S-transferase has been identified. The protein derived from this gene would have 19 amino acid substitutions compared with the GSTA1 isoenzyme. Several pseudogenes with single-base and/or complete exon deletions have been identified, but no reverse-transcribed pseudogenes have been detected. The occurrence of multiple genes and pseudogenes on a single fragment of cloned genomic DNA and the prior identification of a single chromosomal region (6p12) of hybridization (Board and Webb, 1987, Proc. Natl. Acad. Sci. USA 84:2377-2381) suggest that all the Alpha class genes are members of a closely linked gene family that has evolved by duplication and gene conversion events.
我们已经分离并鉴定了编码几种人类α类谷胱甘肽S-转移酶基因和假基因的基因组DNA。所有这些基因均由七个外显子组成，其边界与大鼠α类基因的边界相同。GSTA1基因长度约为12 kb，其两侧紧密排列着其他α类基因序列。已确定上游假基因的外显子7与GSTA1基因的外显子1之间1.7 kb基因间区域的完整序列。已鉴定出另一个编码未表征的α类谷胱甘肽S-转移酶的基因。与GSTA1同工酶相比，该基因衍生的蛋白质将有19个氨基酸替换。已鉴定出几个有单碱基和/或完全外显子缺失的假基因，但未检测到反转录假基因。在克隆的基因组DNA的单个片段上出现多个基因和假基因，以及先前鉴定出的单个杂交染色体区域（6p12）（Board和Webb，1987年，《美国国家科学院院刊》84:2377 - 2381）表明，所有α类基因都是一个紧密连锁的基因家族的成员，该家族通过复制和基因转换事件进化而来。
