Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A putative topoisomerase II gene of African swine fever virus was mapped using a degenerate oligonucleotide probe derived from a region highly conserved in type II topoisomerases. The gene is located within EcoRI fragments P and H of the African swine fever virus genome. Sequencing of this region has revealed a long open reading frame, designated P1192R, encoding a protein of 1192 amino acids, with a predicted molecular weight of 135,543. Open reading frame P1192R is transcribed late after infection into a 4.6-kb RNA. The deduced amino acid sequence of this open reading frame shares significant similarity with topoisomerase II sequences from different sources, with percentages of identity between 23 and 29%. The evolutionary relationships among the topoisomerase II sequences of ASF virus, eukaryotes and prokaryotes were analyzed and a phylogenetic tree was established. The tree indicates that the ASF virus topoisomerase II gene was present in the virus genome before protozoa, yeasts, and metazoa diverged.
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PMID:A gene homologous to topoisomerase II in African swine fever virus. 131 88

Human DNA topoisomerase I not only has DNA relaxing activity, but also splicing factors phosphorylating activity. Topo I shows strong preference for ATP as the phosphate donor. We used photoaffinity labeling with the ATP analogue [alpha-32P] 8-azidoadenosine-5'-triphosphate combined with limited proteolysis to characterize Topo I domains involved in ATP binding. The majority of incorporated analogue was associated with two fragments derived from N-terminal and C-terminal regions of Topo I, respectively. However, mutational analysis showed that deletion of the first 138 N-terminal residues, known to be dispensable for topoisomerase activity, did not change the binding of ATP or the kinase activity. In contrast, deletion of 162 residues from the C-terminal domain was deleterious for ATP binding, kinase and topoisomerase activities. Furthermore, a C-terminal tyrosine 723 mutant lacking topoisomerase activity is still able to bind ATP and to phosphorylate SF2/ASF, suggesting that the two functions of Topo I can be separated. These findings argue in favor of the fact that Topo I is a complex enzyme with a number of potential intra-cellular functions.
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PMID:The C-terminal domain but not the tyrosine 723 of human DNA topoisomerase I active site contributes to kinase activity. 961 Dec 42

A loop-mediated isothermal amplification (LAMP) assay was developed for the detection of African swine fever virus (ASFV). This assay targets the topoisomerase II gene of ASFV and its specificity was confirmed by restriction enzyme digestion of the reaction products. The analytical sensitivity of this ASFV LAMP assay was at least 330 genome copies, and the test was able to detect representative isolates of ASFV (n=38) without cross-reacting with classical swine fever virus. The performance of the LAMP assay was compared with other laboratory tests used for ASF diagnosis. Using blood and tissue samples collected from pigs experimentally infected with ASFV (Malawi isolate), there was good concordance between the LAMP assay and real-time PCR. In addition to detecting the reaction products using either agarose gels or real-time PCR machines, it was possible to visualise dual-labelled biotin and fluorescein ASFV LAMP amplicons using novel lateral flow devices. This assay and detection format represents the first step towards developing a practical, simple-to-use and inexpensive molecular assay format for ASF diagnosis in the field which is especially relevant to Africa where the disease is endemic in many countries.
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PMID:Detection of African swine fever virus by loop-mediated isothermal amplification. 1996 11