Multidrug efflux pump NorC (NorC) (NorC)

NorC is a multidrug efflux pump belonging to the Major Facilitator Superfamily (MFS), specifically identified in Staphylococcus aureus (UniProt Q2FW45). It is characterized as a 14-transmembrane segment protein that utilizes the proton-motive force to drive the extrusion of various substrates, including fluoroquinolones such as norfloxacin and ciprofloxacin, as well as biocides and dyes (Truong-Bolduc et al., 2005, PubMed ID: 16145000). By reducing the intracellular concentration of these agents, NorC plays a critical role in the development of multidrug resistance (MDR) in clinical isolates (Costa et al., 2013, PubMed ID: 23939901). The expression of NorC is often regulated by global regulators like MgrA, which links its activity to the broader stress response and virulence of the pathogen. As a significant contributor to antibiotic failure, NorC is a primary target for the development of efflux pump inhibitors (EPIs) intended to sensitize resistant bacteria to conventional antimicrobial therapies (Kaatz, 2005, PubMed ID: 15992846). This target is particularly relevant in the context of hospital-acquired MRSA infections where limited treatment options remain.

Other names

NorC multidrug transporterNorC proteinStaphylococcus aureus NorC

NorC functions as a proton-motive force-dependent transporter that actively extrudes a variety of structurally unrelated antimicrobial agents from the bacterial cytoplasm to the extracellular environment, thereby lowering the intracellular drug concentration below the threshold required for inhibitory activity (Truong-Bolduc et al., 2005, PubMed ID: 16145000).