Short-chain chromate ion transporter proteins from Bacillus subtilis confer chromate resistance in Escherichia coli.
Tandem paired genes encoding putative short-chain monodomain protein members of the chromate ion transporter (CHR) superfamily (ywrB and ywrA) were cloned from genomic DNA of Bacillus subtilis strain 168. The transcription of the paired genes, renamed chr3N and chr3C, respectively, was shown to occur via a bicistronic mRNA generated from a promoter upstream of the chr3N gene. The chr3N and chr3C genes conferred chromate resistance when expressed in Escherichia coli strain W3110. The cloned chr3N gene alone did not confer chromate resistance on E. coli, suggesting that both chr3N and chr3C genes are required for function. E. coli cells expressing paired chr3N and chr3C genes demonstrated diminished uptake of chromate compared to that by a vector-only control strain. These results suggest that short-chain CHR proteins form heterodimer transporters which efflux chromate ions from the cytoplasm.
Díaz-Magaña
Amada
A
Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana, Morelia, Michoacán.
Aguilar-Barajas
Esther
E
Moreno-Sánchez
Rafael
R
Ramírez-Díaz
Martha I
MI
Riveros-Rosas
Héctor
H
Vargas
Eréndira
E
Cervantes
Carlos
C
D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002840:Chromates / Q000378:metabolism* / Q000494:pharmacology; D003001:Cloning, Molecular; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D015870:Gene Expression; D023061:Gene Order; D007477:Ions / Q000378:metabolism / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009876:Operon; D014158:Transcription, Genetic
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002840:Chromates; D007477:Ions; D026901:Membrane Transport Proteins