::Enzyme Commission number


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{{#invoke:Hatnote|hatnote}} The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze.<ref name="isbn0-12-227164-5">{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> As a system of enzyme nomenclature, every EC number is associated with a recommended name for the respective enzyme.

Strictly speaking, EC numbers do not specify enzymes, but enzyme-catalyzed reactions. If different enzymes (for instance from different organisms) catalyze the same reaction, then they receive the same EC number.<ref name='expasy'>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Furthermore, through convergent evolution, completely different protein folds can catalyze an identical reaction and therefore would be assigned an identical EC number (these are called non-homologous isofunctional enzymes, or NISE).<ref name="pmid20433725">{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> By contrast, UniProt identifiers uniquely specify a protein by its amino acid sequence.<ref name="pmid14681372">{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref>

Enzyme Commission number sections
Intro  Format of number  Top level codes  Reaction Similarity  History  See also  References  External links  

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