Rhea is an expert curated resource of biochemical reactions designed for the annotation of enzymes and genome-scale metabolic networks and models. Rhea uses the ChEBI (Chemical Entities of Biological Interest) ontology of small molecules to precisely describe reactions participants and their chemical structures. All reactions are balanced for mass and charge and are linked to source literature, metabolic resources and other functional vocabularies such as the enzyme classification of the NC-IUBMB.

All data in Rhea is freely accessible and available for anyone to use.

Last release: 99.

Rhea release 99

A new release of Rhea, the annotated database of biochemical reactions, is available...

We are proud to announce that Rhea is now used by UniProtKB to describe enzyme-catalyzed reactions (see announcement).

New: the mapping of ChEBI entities to their protonated state at pH 7.3 is now available as a text file (chebi_pH7_3_mapping.tsv in our download).

Rhea is a collaborative effort between the Swiss-Prot Group at the SIB Swiss Institute of Bioinformatics and the EMBL-EBI.
Rhea makes use of ChemAxon's Marvin tools.