Coordinates the incorporation of A36 into intracellular enveloped virion (IEV) membranes and, subsequently, the production of actin tails. Therefore plays an essential role in efficient cell-to-cell spread of viral particles (By similarity). Homodimer; disulfide-linked. Interacts with B5. Interacts (via C-terminus) with protein A36 (By similarity). Component of the enveloped virion (EV) membrane. Belongs to the chordopoxvirinae A33 protein family.