The product of the cysK gene of Bacillus stearothermophilus V mediates potassium tellurite resistance in Escherichia coli.
The nucleotide sequence of a 4,539 bp fragment of Bacillus stearothermophilus V mediating tellurite resistance in Escherichia coli was determined. Four ORFs of more than 150 amino acids encoding polypeptides of 244, 258, 308, and 421 residues were found in the restriction fragment. E. coli cells harboring a recombinant plasmid containing the Ter determinant express, when challenged with tellurite, a 32 kDa protein with an amino terminal sequence identical to the ten first residues of the 308 ORF. This ORF shows great similarity with the cysteine synthase gene (cysK) of a number of organisms. Recombinant clones carrying the active cysK gene have minimal inhibitory concentrations to K2TeO3 that were tenfold higher than those determined for the host strain or that of clones carrying ORFs 244, 258, and 421. Introduction of the B. stearothermophilus V cysK gene into a cysK strain of Salmonella typhimurium LT2 resulted in complementation of the mutation as well as transfer of tellurite resistance.
Vásquez
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Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile. cvasquez@lauca.usach.cl
Saavedra
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Loyola
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Araya
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Pichuantes
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D003001:Cloning, Molecular; D003547:Cysteine Synthase / Q000235:genetics* / Q000378:metabolism; D015246:Deoxyribonuclease EcoRI / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D012486:Salmonella typhimurium; D017422:Sequence Analysis, DNA; D013691:Tellurium / Q000494:pharmacology*
D029968:Escherichia coli Proteins; C026899:potassium tellurate(IV); D003547:Cysteine Synthase; D015246:Deoxyribonuclease EcoRI; D013691:Tellurium