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APPENDIX Nucleotide Sequences and the Encoded Amino Acids of DNA Topoisomerase Genes

Wai Mun Huang


The nucleotide sequences of DNA topoisomerase genes from many diverse sources have been determined recently. Although the nucleotide sequences of these genes are dissimilar, reflecting differences in codon use, some generalizations are possible regarding the encoded amino acid sequence for each class of topoisomerases. Sequence homology is recognized among all eukaryotic type-I DNA topoisomerases. They are distinct from their prokaryotic counterparts except for the homology of the Saccharomyces cerevisiae TOP3-encoded protein with the prokaryotic type-I proteins. The amino acid sequence homology among type-II enzymes is more extensive and includes all sequenced examples, regardless of source. Detailed discussions of homology can be found in the relevant chapters of this book and in the references of this list. Because these sequences are scattered in the data bases, sometimes under obscure headings, a current list (dated March, 1990) of 7 type-I genes and 15 type-II genes is compiled here. This list, and the corresponding sequences, will be furnished by the author, on request, on floppy diskettes compatible with microcomputers. The compilation will be updated as more sequence information becomes available. Members of the DNA topoisomerase community who would like their topoisomerase gene sequences included in updated compilations should contact the author at the above address.

The compiled DNA sequences provide only the coding information of these genes. Introns and the terminating codon of the genes are not included. Readers should refer to the original publications for flanking sequences and other characteristics of the genes. The size of the genes is given in number...

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