Outer capsid protein involved in attachment and possibly entry into the host epithelial cell. It is subsequently lost, together with VP4, following virus entry into the host cell. The outer layer contains 780 copies of VP7, grouped as 260 trimers. Rotavirus attachment and entry into the host cell probably involves multiple sequential contacts between the outer capsid proteins VP4 and VP7, and the cell receptors (By similarity). Homotrimer; in the presence of calcium (By similarity). Acquisition of the capsid outer layer requires a high calcium concentration inside the endoplasmic reticulum. Following cell entry, the low calcium concentration in the cytoplasm is probably responsible for the solubilization of the outer layer (By similarity). Immature double-layered particles assembled in the cytoplasm bud across the membrane of the endoplasmic reticulum, acquiring during this process a transient lipid membrane that is modified with the ER resident viral glycoproteins NSP4 and VP7; these enveloped particles also contain VP4. As the particles move towards the interior of the ER cisternae, the transient lipid membrane and the non-structural protein NSP4 are lost, while the virus surface proteins VP4 and VP7 rearrange to form the outermost virus protein layer, yielding mature infectious triple-layered particles (By similarity). Belongs to the rotavirus VP7 family.