Molecular function

flippase activity (exoplasmic to cytosolic leaftlet)

Catalysis of the movement of lipids from the exoplasmic to the cytosolic leaftlet of a membrane, using energy from the hydrolysis of ATP.

Nomenclature note. Flippases and floppases are ATP-dependent transbilayer lipid translocators. According to an extensively used, though not universal, nomenclature, they catalyze lipid transfer towards the inward monolayer (flippases) or towards the outward monolayer (floppases). Scramblases are ATP-independent, non-selective, inducing non-specific transbilayer movements across the membrane. The direction of the translocation should be taken into account for annotation (from the exoplasmic to the cytosolic leaftlet of a membrane).