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Rhea release 117

Published February 10, 2021

Rhea web site

Structure search: to make the result page more self-contained, the 2D structure of the query and the search parameters have been added to the result page.

Rhea release 115

Published October 7, 2020

New website

We are proud to announce the release of our new website: a new interface, a new search engine and many new options to serve you better. We welcome your feedback!

Cross-references to UniProt

The mapping to all UniProt enzyme sequences is now available for download on our FTP site:

Rhea release 99

Published December 6, 2018

Rhea in UniProt 'Catalytic activity' annotations

Starting from this release, Rhea reactions are used in UniProt for 'Catalytic activity' annotations. See the UniProt 2018_11 news for more details.

Changes to cross-references to UniProt

UniProt now provides direct links between proteins (UniProtKB entries) and Rhea reactions. These data are searchable and downloadable from the UniProt website. As a consequence, we stopped displaying the old indirect cross-references that were computed via EC numbers (Rhea - EC - UniProtKB/Swiss-Prot) on our website and removed the corresponding file rhea2uniprot.tsv from our FTP site. We also replaced the BioPAX files rhea-biopax_lite.owl.gz and rhea-biopax_full.owl.gz by a single file rhea-biopax.owl.gz, which no longer contains links to UniProtKB/Swiss-Prot entries.

ChEBI major microspecies at pH 7.3

The mapping of ChEBI entities to their protonation state at pH 7.3 is now available for download: chebi_pH7_3_mapping.tsv

Rhea release 90

Published January 31, 2018

Change to alphabetic sorting of reaction participants

Starting with this release, the participants on each side of a reaction are sorted alphabetically (case insensitive) by their name (in ASCII representation).

L-glutamine + chorismate = L-glutamate + anthranilate + H(+) + pyruvate

chorismate + L-glutamine = anthranilate + H(+) + L-glutamate + pyruvate

This affects the website, APIs and FTP downloads.

Rhea release 88

Published November 22, 2017

Change of EC cross-references from bidirectional to reactions with undefined direction

The cross references from Rhea reactions to EC numbers have been moved from bidirectional reactions (<=>) to reactions with undefined direction (=).


a primary alcohol + NAD() <=> an aldehyde + H() + NADH
Cross reference: EC


a primary alcohol + NAD() = an aldehyde + H() + NADH
Cross reference: EC

This affects the website, APIs and FTP downloads.

The file ec-rhea-dir.tsv has been removed from the FTP site, the files rhea-ec-iubmb.tsv and rhea2ec.tsv remain available.

Rhea release 85

Published August 30, 2017

Change of symbol for reactions with undefined direction

The symbol in reactions with undefined direction ("master" reactions) has been changed from "<?>" to the equals sign "=".

Old format: A + B <?> C + D
New format: A + B = C + D

This affects the website, API and FTP downloads.