(C4): The structurally constrained neutral model of protein evolution
U. Bastolla, M. Porto, H.E. Roman, and M. Vendruscolo, in Structural approaches to sequence evolution: Molecules, networks, populations, edited by U. Bastolla, M. Porto, H.E. Roman, and M. Vendruscolo, Springer, Berlin, 2007, pp. 75-113.
The structural profile, as discussed in this chapter, can be downloaded from the SLOTH homepage for each structure of the PDB.