The recombinant nucleocapsid data indicates that both VP35-VP30-VP24-NP and VP35-VP24-NP produce approximately 50 nm diameter helical structures that are indistinguishable from nucleocapsids produced by EBOV. This indicates that VP30 does not increase the diameter of the nucleocapsid. We propose that VP30 lies in the interior of the nucleocapsid and is not part of the bridge on the periphery of the nucleocapsid. This localization is consistent with previous work showing that VP30 is a component of the nucleocapsid, and associates with NP, but is non-essential for nucleocapsid formation [14, 30, 31] . Our model, in which the inner layer at 22.3 nm diameter is RNA-NP, and the outer bridge centered at 37 nm is composed of VP24-VP35 heterodimers, with VP30 bound to NP, is thus consistent with these previous observations [14, 28, 29] , and suggests that the outer VP24-VP35 heterodimer bridge functions in the stabilization and/or protection of the nucleocapsid.