About the CGSC 
 Searching the CGSC Database 
 How to Request Strains or Information
 
 Site - topASite topA Site topA
- Name: topA
- Type: Gene                          - Synonyms
|
 | b1274 | MG1655 locus tag |  | supX |  |  
 
 
- Mnemonic: topoisomerase
- Left End Point: 28.65
- Right End Point: 28.71
 
- Direction: >
- Priority: 1
 
- External Database Links:
 
- Comment: - Selectable phenotype.  Loss:  deleted with trp, opp; streptomycin, kanamycin, neomycin resistance. TopoI-neg strains exhibit hypernegative supercoiling of plasmids (Pruss 1985).
 
- References: - Dubnau, E., P. Margolin 1972. Suppression of promoter mutations by the pleiotrophic supX mutations. Mol.Gen.Genet. 117:91-112
 
- Lenny, A.B., P. Margolin 1980. Locations of the opp and supX genes of Salmonella typhimurium and Escherichia coli. J.Bacteriol. 143:747-752
 
- Sternglanz, R., S. DiNardo, K.A. Voelkel, Y. Nishimura, Y. Hirota, K. Becherer, L. Zumstein, J.C. Wang 1981. Mutations in the gene coding for Escherichia coli DNA topoisomerase I affect transcription and translation. Proc.Natl.Acad.Sci.USA 78:2747-2751
 
- Trucksis, M., D.J. Zabel, R.E. Depew 1981. Escherichia coli and Salmonella typhimurium supX genes specify deoxyribonucleic acid topoisomerase. J.Bacteriol. 147:679-681
 
- Trucksis, M., R.E. Depew 1981. Identification and localization of a gene that specifies production of Escherichia coli DNA topoisomerase. Proc.Natl.Acad.Sci.USA 78:2164-2168
 
- Wang, J.C., K. Becherer 1983. Cloning of the gene topA encoding for DNA topoisomerase I and the physical mapping of the cysB-topA-trp region of Escherichia coli. Nucleic Acids Res. 11:1773-1790
 
- Margolin, P., L. Zumstein, R. Sternglanz, J.C. Wang 1985. The Escherichia coli supX locus in topA, the structural gene for DNA topoisomerase I. Proc.Natl.Acad.Sci.USA 82:5437-5441
 
- Tse-Dinh, Y.C., J.C. Wang 1986. Complete nucleotide sequence of the topA gene encoding Escherichia coli DNA topoisomerase I. J.Mol.Biol. 191:321-331
 
- Ostrowski, J., G. Jagura-Burdzy, N.M. Kredich 1987. DNA sequences of the cysB regions of Salmonella typhimurium and Escherichia coli. J.Biol.Chem. 262:5999-6005
 
- Biek, D.P., S.N. Cohen 1989. Involvement of integration host factor (IHF) in maintenance of plasmid pSC101 in Escherichia coli: mutations in the topA gene that allow pSC101 replication in the absence of IHF. J.Bacteriol. 171:2066-2074
 
- Oram, M., L.M. Fisher 1992. An Escherichia coli DNA topoisomerase I mutant has a compensatory mutation that alters two residues between functional domains of the DNA gyrase A protein. J.Bacteriol. 174:4175-4178
 
- Lynch, A.S., J.C. Wang 1993. Anchoring of DNA to the bacterial cytoplasmic membrane through cotranscriptional synthesis of polypeptides encoding membrane proteins or proteins for export:a mechanism of plasmid hypernegative supercoiling in mutants defic
 
- Perry, K., A. Mondragon 2002. Biochemical characterization of an invariant histidine involved in Escherichia coli DNA topoisomerase I catalysis. J.Biol.Chem. 277:13237-13245