The structure of a prokaryotic viral envelope protein expands the landscape of membrane fusion proteins by El Omari, K, Li, S, Kotecha, A, Walter, T, Bignon, E, Harlos, K, Somerharju, P, De Haas, F, Clare, D, Molin, M, Hurtado, F, Li, M, Grimes, J, Bamford, D, Tischler, N, Huiskonen, J, Stuart, D, Roine, E