An Ochrobactrum anthropi gene conferring paraquat resistance to the heterologous host Escherichia coli.
A new gene, pqrA, conferring paraquat resistance to the heterologous host Escherichia coli, from a chromosomal DNA library of Ochrobactrum anthropi JW2, was cloned and analyzed. Cells of E. coli transformed with a plasmid carrying the pqrA gene showed elevated resistance to paraquat, but not to hydrogen peroxide. The predicted amino acid sequence of the PqrA polypeptide showed 71% identity with mll7495 hypothetical membrane protein in Mesorhizobium loti, 49% identity with PA2269 protein in Pseudomonas aeruginosa, and significant identity with other previously reported drug transport proteins. The hydropathy pattern of the PqrA polypeptide showed a significant homology to those of 12-transmembrane-segment (TMS) family export proteins. Immunoblot analysis demonstrated that the PqrA protein found in the membrane protein fraction of O. anthropi JW2 has a molecular mass of 42 kDa. These results suggest that the PqrA protein is a membrane protein that plays an important role in protecting cells against paraquat toxicity.
Won
S H
SH
Department of Animal Science and Biotechnology, College of Agriculture, Kyungpook National University, Sankyukdong, Pukku, Taegu, 702-701, Korea.
Lee
B H
BH
Lee
H S
HS
Jo
J
J
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D005798:Genes, Bacterial; D006540:Herbicides / Q000494:pharmacology*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010269:Paraquat / Q000494:pharmacology*; D012230:Rhizobiaceae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D006540:Herbicides; D008565:Membrane Proteins; C433240:PqrA protein, Ochrobactrum anthropi; D010269:Paraquat