Molecular analysis of yeast and human type II topoisomerases. Enzyme-DNA and drug interactions.
The DNA sequence selectivity of topoisomerase II (top2)-DNA cleavage complexes was examined for the human (top2alpha), yeast, and Escherichia coli (i.e. gyrase) enzymes in the absence or presence of anticancer or antibacterial drugs. Species-specific differences were observed for calcium-promoted DNA cleavage. Similarities and differences in DNA cleavage patterns and nucleic acid sequence preferences were also observed between the human, yeast, and E. coli top2 enzymes in the presence of the non-intercalators fluoroquinolone CP-115,953, etoposide, and azatoxin and the intercalators amsacrine and mitoxantrone. Additional base preferences were generally observed for the yeast when compared with the human top2alpha enzyme. Preferences in the immediate flanks of the top2-mediated DNA cleavage sites are, however, consistent with the drug stacking model for both enzymes. We also analyzed and compared homologous mutations in yeast and human top2, i.e. Ser(740) --> Trp and Ser(763) --> Trp, respectively. Both mutations decreased the reversibility of the etoposide-stabilized cleavage sites and produced consistent base sequence preference changes. These data demonstrate similarities and differences between human and yeast top2 enzymes. They also indicate that the structure of the enzyme/DNA interface plays a key role in determining the specificity of top2 poisons and cleavage sites for both the intercalating and non-intercalating drugs.
Strumberg
D
D
Laboratory of Molecular Pharmacology, Division of Basic Sciences, NCI, National Institutes of Health, Bethesda, Maryland 20892-4255, USA.
Nitiss
J L
JL
Dong
J
J
Kohn
K W
KW
Pommier
Y
Y
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000378:metabolism*; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D017931:DNA Primers; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology; D006801:Humans; D016297:Mutagenesis, Site-Directed; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D017931:DNA Primers; D004268:DNA-Binding Proteins; D004247:DNA; D004250:DNA Topoisomerases, Type II; D002118:Calcium