Structural component of the virion that forms triskelion structures consisting of three molecules that stabilize three hexon trimers at the center of each icosahedral facet and fixes the peripentonal hexons (By similarity). Dispensable for assembly. During virus entry, recruits the anterograde motor kinesin-1 to the capsid docked at the nuclear pore complex thereby subjecting the docked capsid to a pulling force (PubMed:21925109). The resulting tension leads to capsid disruption, dispersion of capsid fragments toward cell periphery and eventually viral DNA entry into the host nucleus (PubMed:21925109). Homotrimer (By similarity). Interacts with hexon protein; this interaction tethers the hexons together (By similarity). Self-interacts with adjacent proteins (By similarity). Interacts with kinesin light chain KLC1; this interaction leads to capsid disruption at the nuclear pore complex during virus entry into host cell (PubMed:21925109). Located in the canyons between the hexons on the outer surface of the capsid. Forms a sort of hairnet on the outer side of the virion. Present in 240 copies per virion. Expressed in the intermediate phase of the viral replicative cycle. Three N-terminal domains of hexon-interlacing protein form triskelions between hexon capsomers. This protein is only encoded by mastadenoviruses, and may therefore play a role in mammals tropism. Belongs to the adenoviridae hexon-interlacing protein family.