An Ochrobactrum anthropi gene conferring paraquat resistance to the heterologous host Escherichia coli

作者：Won SH; Lee BH; Lee HS; Jo J^*

来源：Biochemical and Biophysical Research Communications, 2001, 285(4): 885-890.

DOI：10.1006/bbrc.2001.5268

• active oxygen species
• membrane protein
• Ochrobactrum anthropi
• paraquat resistance

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 ml17495 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.

• 出版日期2001-7-27