Hsieh T S, Lee M P, Nolan J M, Wyckoff E
NCI Monogr. 1987(4):7-10.
The gene encoding the Drosophila type II DNA topoisomerase has been isolated and characterized. The enzyme is coded for by a messenger RNA of about 5000 nucleotides, the expected size for the enzyme with MWr 170,000, and the gene is interrupted by four introns. The cytogenetic location of this gene has been mapped to the left arm of chromosome 2 at 37D2-6 by both in situ hybridization to polytene chromosomes and genomic blot-hybridization. The complete nucleotide sequence of the coding region and the flanking sequence has been determined. The deduced amino acid sequence shows interesting homology with topoisomerases II from bacteria, bacteriophage T4, and yeasts. The sequence homology between the Drosophila enzyme and those from Saccharomyces and Schizosaccharomyces is very extensive. This, in combination with the similar biochemical properties among all the eucaryotic DNA topoisomerases II, indicates that these enzymes are conserved during the course of evolution.
编码果蝇II型DNA拓扑异构酶的基因已被分离和鉴定。该酶由约5000个核苷酸的信使核糖核酸编码，这是分子量为170,000的该酶的预期大小，并且该基因被四个内含子中断。通过对多线染色体的原位杂交和基因组印迹杂交，该基因的细胞遗传学定位已被定位于2号染色体左臂的37D2 - 6处。已确定编码区和侧翼序列的完整核苷酸序列。推导的氨基酸序列显示出与细菌、噬菌体T4和酵母的拓扑异构酶II有趣的同源性。果蝇酶与酿酒酵母和裂殖酵母的酶之间的序列同源性非常广泛。这与所有真核DNA拓扑异构酶II之间相似的生化特性相结合，表明这些酶在进化过程中是保守的。
