ATP hydrolysis at one of the two sites in ABC transporters initiates transport related conformational transitions

► We perform molecular dynamics simulations with two conformations of ABC transporters. ► Dynamics of the ATP/ATP and ATP/ADP bound outward-facing conformations differs. ► Outward-facing conformation can switch to MsbA-like bottom-closed apo conformation. ► The inward-facing structure may be a short-living transient conformation.