E. coli GyrA Tower Domain Interacts with QnrB1 Loop B and Plays an Important Role in QnrB1 Protection from Quinolone Inhibition [Mechanisms of Resistance]

xloma.fota13 shared this article with you from Inoreader E. coli GyrA Tower Domain Interacts with QnrB1 Loop B and Plays an Important Role in QnrB1 Protection from Quinolone Inhibition [Mechanisms of Resistance] Via AAC Accepts: Articles Published Ahead of Print The Qnr pentapeptide repeat proteins interact with DNA gyrase and protect it from quinolone inhibition. The two external loops, particularly the larger loop B, of Qnr proteins are essential for quinolone protection of DNA gyrase. The specific QnrB1 interaction sites on DNA gyrase are not known. In this study, we investigated the interaction between GyrA and QnrB1 using site-specific photo crosslinking of QnrB1 loop B combined with mass spectrometry. We found that amino acid residues 286-298 on the Tower domai n of GyrA interact with QnrB1 and play a key role in QnrB1 protection of gyrase from quinolone inhibition. Alanine replacement of arginine at residue 293 and a small deletion of amino acids 286-289 of GyrA resulted in a decrease in the QnrB1-mediated increase in quinolone MICs and also abolished the QnrB1 protection of purified DNA gyrase from ciprofloxacin inhibition. View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.