Markov random field for interaction graph in Figure 2. This figure illustrates the corresponding Markov random field structure of the interaction graph from Figure 2. Square nodes are backbone random variables for which conformation is known and circular nodes are side-chain random variables for which conformation is unknown. x
denotes the backbone conformation of the i th residue. Since this is given, the variable is not capitalized. X
denotes the side-chain conformation R
of the i th residue. Since this is not given, the variable is capitalized.