INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY
INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY
IUPAC-IUBMB Joint Commission on Biochemical Nomenclature (JCBN)
Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)
World Wide Web home page maintained by G. P. Moss
School of Physical and Chemical Sciences, Queen Mary University of London,
Mile End Road, London, E1 4NS, UK
They make recommendations with this aim. The committees seek advice from experts in the diverse fields of biochemistry about matters where communication is difficult because of inconsistent practices. This is the starting point of most of the initiatives of the committees. The experts consulted include journal editors and database managers. For example, the recommendations for a Nomenclature for Incompletely Specified Bases in Nucleic Acid Sequences (1984) arose out of an attempt by an international group of experts to resolve the confusion that previously resulted from the existence of many different systems to represent combinations such as "G or C", which had been written in at least five different ways.
In practice there is considerable overlap in the tasks of the two committees and they always work and meet as a single body, with a common Chairman and a common Secretary. The present members are listed on the web. Unless otherwise indicated, therefore, the term "nomenclature committees" in this page refers equally to JCBN and to NC-IUBMB.
A list of JCBN and NC-IUBMB publications is available through the web, and the full texts of the following are also there. Others will be added as time permits.
|Amino Acids and Peptides||https://iupac.qmul.ac.uk/AminoAcid/|
|Branched nucleic acids||https://iubmb.qmul.ac.uk/misc/bran.html|
|Corrinoids (vitamin B12)||https://iupac.qmul.ac.uk/misc/B12.html|
|Electron transport proteins||https://iubmb.qmul.ac.uk/etp/|
|EC 1 Oxidoreductases||https://iubmb.qmul.ac.uk/enzyme/EC1/|
|EC 2 Transferases||https://iubmb.qmul.ac.uk/enzyme/EC2/|
|EC 3 Hydrolases||http://iubmb.qmul.ac.uk/enzyme/EC3/|
|EC 4 Lyases||https://iubmb.qmul.ac.uk/enzyme/EC4/|
|EC 5 Isomerases||https://iubmb.qmul.ac.uk/enzyme/EC5/|
|EC 6 Ligases||https://iubmb.qmul.ac.uk/enzyme/EC6/|
|Membrane transport proteins||https://iubmb.qmul.ac.uk/mtp/|
|Multiple forms of enzymes||http://www.sbcs.qmul.ac.uk/iubmb/misc/isoen.html|
|Nucleic acid constituents||https://iupac.qmul.ac.uk/misc/naabb.html|
|Nucleic acid sequence|
(incompletely specified bases)
|Phosphorus containing compounds||https://iupac.qmul.ac.uk/misc/phospho.html|
|Polymerized amino acids||https://iupac.qmul.ac.uk/misc/polypep.html|
|Pyridoxal (vitamin B6)||https://iupac.qmul.ac.uk/misc/B6.html|
|Quinones with an Isoprenoid Chain||https://iupac.qmul.ac.uk/misc/quinone.html|
|Tocopherols (vitamin E)||https://iupac.qmul.ac.uk/misc/toc.html|
|Chemical recommendations of use to biochemists|
|Gold Book - chemical glossary||iupac.qmul.ac.uk/bibliog/gold.html|
|Medicinal chemistry glossary||iupac.qmul.ac.uk/medchem/|
|Natural product nomenclature||iupac.qmul.ac.uk/sectionF/|
|Physical organic chemistry glossary||iupac.qmul.ac.uk/gtpoc/|
See A brief guide to nomenclature and classification of enzymes
New enzymes, corrections and reclassified enzymes are list in batches for four weeks before being added to the lists. The last batch was posted in April 2021.
Enzymes are classified as:
This site is searchable. It contains the recommended name and number of each enzyme. An increasing fraction of these entries have links to the specifications of the enzymes, allowing these to be obtained on screen. These specifications include links to other bioinformatic databases as well as references and comments on the nature of the enzymes. It includes all enzymes approved or updated since the 1992 edition of Enzyme Nomenclature.
current transferred deleted EC 1 oxidoreductases 1931 420 93 EC 2 transferases 1958 86 84 EC 3 hydrolases 1318 363 111 EC 4 lyases 709 79 31 EC 5 isomerases 306 13 10 EC 6 ligases 232 6 9 EC 7 translocases 93 0 0
It is perhaps worth noting, as it has been a matter of long-standing confusion, that enzyme nomenclature is primarily a matter of naming reactions catalysed, not the structures of the proteins that catalyse them. This has allowed assignment of newly-discovered catalytic activities before anything is known about the structures of the enzymes. The links to databases of genes and protein structure allow the relationships between functional and structural classifications to be more readily accessed. The system of naming enzymes in terms of reactions, rather than structures, is one that works far better for enzymes that act on relatively small molecules than for those that handle polymers. Because of this a rather different system is used for the nomenclature of peptidases.
Information about new enzymes or corrections to existing entries may be reported directly from these web pages or by using the form printed in the back of of the 1992 edition of Enzyme Nomenclature. Comments and suggestions on enzyme classification and nomenclature also may be sent to Dr Andrew McDonald (Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland). All new material is considered by the committees before approval. The work on enzyme nomenclature and its transfer to the web have been greatly facilitated by grants to K.F. Tipton from the European Commission (Framework 4 Programme) and the National Institutes of Health.
Any subject can be reexamined, and it is open to any biochemist or other scientist concerned with biochemistry to draw attention to problem areas, whether because no conventions exist or because the existing recommendations fail to take account of the current state of knowledge. The most efficient way to do this is to write to the contact the Secretary of JCBN and NC-IUBMB, Professor R. Caspi, outlining the problem, and when appropriate suggesting a possible solution.
Comments and corrections to the Secretary Professor R. Caspi
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