Analysis of Protein–Protein Functional Associations by Using Gene Ontology and KEGG Pathway

Figure 1

The whole procedures for analyzing protein–protein functional associations based on gene ontology (GO) and KEGG pathways. The raw 2,425,314 human PPIs were retrieved from STRING and refined by excluding similar proteins and selecting those validated by experiments, resulting in 70,392 PPIs. 6,623 proteins were involved in investigated PPIs and used to construct ten sets of protein pairs, each of which combined with 70,392 PPIs to constitute ten datasets. Each sample was represented by GO and KEGG features, which were evaluated by mutual information, producing ten feature lists, from which we extracted most important features, corresponding to 134 GO terms and one KEGG pathway.