A functional annotation and its prediction. This Figure shows one annotation of a sample protein A and its prediction. Each node in a graph corresponds to one GO term and the edges to relationships such as "is a" or "part of". The edges always point to the root node (either "MFO" or "BPO"), which by itself is not informative and discarded in every evaluation. For clearity, the left subgraph only shows the experimental annotation of A. This means, all GO terms have either been experimentally verified or inferred from the same. The red circles indicate the leaf terms, i.e. the nodes which are not a parent of any other term. In the right subgraph, we see the experimental annotation again, but overlaid with predicted terms (green) and their reliabilities. This time, the leaf terms correspond to the predicted GO annotation, instead of the actual annotation.
Hamp et al. BMC Bioinformatics 2013 14(Suppl 3):S7 doi:10.1186/1471-2105-14-S3-S7