Mapping functional residues to HMM states. Each column in the globin alignment maps to either match or insert state, including the columns that represent functional sites. The columns labeled by As represents active site positions, whereas Bs columns represents binding site positions. M
represent match, insert and delete states in HMM architecture, respectively. In this illustration, As1 mapped to M8 state, and the Bs1, Bs2 and Bs3 columns mapped to M2, M13 and I15 states, respectively.