Figure 9
From: Using hidden Markov models to investigate G-quadruplex motifs in genomic sequences
The HMM-based model 1. In the figure, a letter surrounded on four sides indicates a hidden state for emitting that letter. Specifically, "G" is the hidden state for G-runs; "N" is the hidden state for the interconnecting loops; "begin" state shows the start of the motif; and "end" state denotes the end of the motif. Note that the "begin" and "end" states actually generate no symbols. An arrow between two hidden states shows state transition. Note that a probability parameter is given to each transition. This model is designed as simple as possible, where at least two Gs are emitted from two states for each G-run and zero or more bases are allowed to emit from each loop state.