Quinolone resistance protein NorA (NorA)

Quinolone resistance protein NorA is a proton-coupled multidrug efflux transporter found in *Staphylococcus aureus* and belongs to the major facilitator superfamily (MFS)[5][7][8]. NorA actively exports a wide range of antibiotics and toxic compounds out of bacterial cells using a proton gradient, most notably conferring resistance to fluoroquinolones such as norfloxacin and ciprofloxacin[1][4][8]. Overexpression of NorA in S. aureus leads to multidrug resistance phenotypes, and its action is a key barrier to the successful treatment of MRSA infections[3][8]. NorA has become a target for developing efflux pump inhibitors, which could synergize with existing antibiotics to combat resistance[5][8]. The NorA family is defined by structural motifs conserved among MFS transporters, including essential acidic residues (Glu222 and Asp307) that mediate proton coupling and substrate recognition[8].

Other names

NorA efflux pumpNorA multidrug transporterStaphylococcus aureus NorAMultidrug resistance protein NorAMFS NorA

Drug/H+ antiporter: NorA pumps out antimicrobials and other substrates in exchange for protons, lowering the intracellular concentration of drugs and conferring resistance[1][6][8].