MurJ/MviN, a subfamily of the multidrug and toxic compound extrusion (MATE)-like proteins
Escherichia coli MurJ (MviN) has been identified as essential for murein biosynthesis. It has been suggested that MurJ functions as the peptidoglycan lipid II flippase which is involved in translocation of lipid-anchored peptidoglycan precursors across the cytoplasmic membrane, though results obtained in Bacillus subtilis seem to indicate that its MurJ homologs are not essential for growth. Some MviN family members (e.g. in Mycobacterium tuberculosis) possess an extended C-terminal region that contains an intracellular pseudo-kinase domain and an extracellular domain resembling carbohydrate-binding proteins. Proteins from the MATE family are involved in exporting metabolites across the cell membrane and are often responsible for multidrug resistance (MDR).