“…Like many enveloped viruses such as rhabdovirus (11) and arenaviruses (44), Ebola virus encodes late-assembly or L domains, which are sequences required for the membrane fission event that separates viral and cellular membranes to release nascent virion particles (1,5,7,10,12,18,25,27,34). Thus far, four classes of L domains have been identified which were defined by their conserved amino acid core sequences: the Pro-Thr/ Ser-Ala-Pro (PT/SAP) motif (25,27), the Pro-Pro-x-Tyr (PPxY) motif (11,12,18,19,41,53), the Tyr-x-x-Leu (YxxL) motif (3,15,27,37), and the Phe-Pro-Ile-Val (FPIV) motif (39). Both PTAP and the PPxY motifs are essential for efficient particle release for eVP40 (25,27,48,49), whereas mVP40 contains only a PPxY motif.…”