The Ebola Virus matrix protein, VP40, of 328 aas. It promotes virus assembly and budding by interacting with host lipids as well as proteins of the multivesicular body pathway and facilitates virus budding by interacting with the nucleocapsid and the plasma membrane. Specific interactions with membrane-associated GP and VP24 during the budding process also occurs. The hexamer seems to be involved in budding while the octamer binds RNA (Johnson et al. 2006). The high resolution structure of the N-terminal domain with RNA is available (1H2C_A) (Radzimanowski et al. 2014).  In vitro, it catalyzes lipid flipping and therefore could be a flippase or a scramblase (RV Stahelin, personal communication). See family description for more details.