Mediates antimicrobial resistance via active efflux. Contributes to resistance to antibiotics such as chloramphenicol, erythromycin and novobiocin (PubMed:21212056). May be part of a tripartite ATP-independent periplasmic (TRAP) transport system (Probable). Deletion of the gene results in increased susceptibility to different antibiotics, dyes, detergents and disinfectants. Belongs to the bacterial solute-binding protein 7 family.