Protein modification

OntoBee AberOWL OLS BioPortal Bioregistry

PSI-MOD is an ontology consisting of terms that describe protein chemical modifications, logically linked by an is_a relationship in such a way as to form a direct acyclic graph (DAG). The PSI-MOD ontology has more than 45 top-level nodes, and provides alternative hierarchical paths for classifying protein modifications either by the molecular structure of the modification, or by the amino acid residue that is modified.