Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)

Enzyme Nomenclature. Recommendations 1992

Enzyme Supplement 5 (1999)

Update to Enzyme Nomenclature List

Prepared for the NC-IUBMB by Keith Tipton and Sinéad Boyce, Department of Biochemistry, Trinity College, Dublin 2, Ireland.

This document contains new enzyme listings plus amendments to existing enzymes, as listed in Enzyme Nomenclature 1992 [Academic Press, San Diego, California, ISBN 0-12-227164-5 (hardback), 0-12-227165-3 (paperback)]. This supplement is as close as possible to the published version [see Eur. J. Biochem., 1999, 264, 610-650 ]. If you need to cite this supplement please quote this references as its source.

World Wide Web version prepared by G.P. Moss
Department of Chemistry, Queen Mary University of London,
Mile End Road, London, E1 4NS, UK

Important Note: This version is formatted using the font symbol for Greek letters. If you cannot see a Delta (a triangle) in quotation marks next "δ" click here for a version where Greek letters are created using graphic images.

The data will also be incorporated in a modified form into the SWISSPROT ENZYME ( Information about new enzymes or corrections to existing entries also may be reported directly from these web pages or by using the form printed in the back of Enzyme Nomenclature. Comments and suggestions on enzyme classification and nomenclature may be sent to Professor K.F. Tipton ( or Dr S. Boyce, Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland (

Contents - New Entries and Corrections

EC 1 Oxidoreductases
EC 2 Transferases
EC 3 Hydrolases (excluding peptidases)
EC 4 Lyases
EC 5 Isomerases
EC 6 Ligases

Additional corrections and Glossary


Reference 2975: page number 8283 not 8285

Reference 3291: year 1987 not 1988; volume number 262 not 263

Reference 5559 does not refer to EC and, does refer to


4-HydroxycatecholBenzene-1,2,4-triol, 1,2,4-trihydroxybenzene
2-Hydroxymuconate semialdehyde2-Hydroxy-6-oxohexa-2,4-dienoate
2-HydroxyquinolineQuinolin-2-ol exists largely as the quinolin-2(1H)-one tautomer.
4-HydroxyquinolineQuinolin-4-ol exists largely as the quinolin-4(1H)-one tautomer.
OrganylAny organic substituent group, regardless of functional type, having one free valence at a carbon atom
Phenazine methosulfate5-Methylphenazinium methyl sulfate
PAdoPSPhosphoadenosine phosphosulfate
PAdoPPhosphoadenosine phosphate

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