A schematic representation of EBOV viral protein 40 (VP40). VP40 aa 7–13 consists of two late budding domains (L-domains), namely PTAP (aa 7–10) and PPEY (aa 10–13). Both L-domains are crucial to viral budding. VP40 aa 52–65, 95, 108–117, and 160 are involved in dimerization, while aa 303–307 enables VP40–Sec24C interaction. Both the dimerization state and the interaction with Sec24C are significant for proper cellular trafficking of VP40. The binding of octameric VP40 to ssRNA (via VP40 aa 125 and 134) negatively regulates transcription. aa 326 provides stability to VP40 via interaction with host SUMO protein.