title: Cloning and characterization of the Aspergillus nidulans DNA topoisomerase I gene.
abstract: The topoisomerase I (TOP1) gene was cloned and sequenced from Aspergillus nidulans using the polymerase chain reaction (PCR). Genomic DNA was used as a template to obtain a 2987-bp gene containing five small introns. PCR from a cDNA library yielded a 2613-bp sequence which codes for an 871 amino acid protein. Comparison of the deduced amino acid sequence with other DNA topoisomerase I (topo I) protein sequences shows a somewhat higher degree of identity with other fungal amino acid sequences than with the human enzyme. Topo I is a ubiquitous enzyme which can be converted to a cytotoxic molecule in the presence of drugs that function as topo I poisons. The Aspergillus TOP1 cDNA will be used in an effort to identify novel cytotoxic antifungals which target this enzyme.
authors.affiliation: Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway 08855, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Van Dross
authors.forename: K V
authors.initials: KV
authors.lastname: Rao
authors.forename: E
authors.initials: E
authors.lastname: Eisenberg
authors.forename: M M
authors.initials: MM
authors.lastname: Sanders
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000494:pharmacology; D001228:Aspergillosis / Q000188:drug therapy; D001233:Aspergillus nidulans / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004264:DNA Topoisomerases, Type I / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D059004:Topoisomerase I Inhibitors
chemical_list: D000935:Antifungal Agents; D004791:Enzyme Inhibitors; D059004:Topoisomerase I Inhibitors; D004264:DNA Topoisomerases, Type I