VERSATILE LEGO. “For most capsids with HK97-like coat proteins, chemically identical subunits occupy non-identical sites in the icosahedron. This relies on coat protein plasticity as well as a mechanism by which identical subunits can be “switched” into slightly different conformations required to occupy quasi-equivalent sites in the icosahedron, a process known as conformational switching.”
http://www.sciencedirect.com/science/article/pii/S0042682215001920