UniProt

Homepage Link: https://www.uniprot.org/help/about

Description: The Universal Protein Resource (UniProt) is the world’s leading high-quality, comprehensive and freely accessible resource of protein sequence and functional information. The UniProt Knowledgebase (UniProtKB) includes both manually-curated and automatically-annotated data.

Example record: Homogentisate 1,2-dioxygenase (HGD, human) UniProtKB:Q93099 catalyzes the reaction "homogentisate + O2 = 4-maleylacetoacetate + H(+)" RHEA:15449. See "Catalytic activity" section of HGD's entry