EC number

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EC number

This article is about the Enzyme Commission codes. For the European Commission system for coding chemicals, see EC-No
EC-No

The "European Commission number", or EC number, also known as EC-No and EC#, is the seven-digit code that is assigned to chemical substances that are commercially available within the European Union....
.

The Enzyme Commission number (EC number) is a numerical classification

Numbering scheme

There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator....
scheme for enzyme

Enzyme

Enzymes are biomolecules that catalysis chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are called Substrate , and the enzyme converts them into different molecules, the products....
s, based on the chemical reaction

Chemical reaction

A chemical reaction is a process that always results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants....
s they catalyze

Catalysis

Catalysis is the process in which the reaction rate of a chemical reaction is either increased or decreased by means of a chemical substance known as a catalyst....
. 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.

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Encyclopedia

The Enzyme Commission number (EC number) is a numerical classification

Numbering scheme

There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator....
scheme for enzyme

Enzyme

Chemical reaction

Catalysis

UniProt

UniProt is the universal protein resource, a central repository of protein data created by combining Swiss-Prot, TrEMBL and Protein Information Resource....
identifiers uniquely specify a protein by its amino acid sequence.

Format of number

Every enzyme code consists of the letters "EC" followed by four numbers separated by periods. Those numbers represent a progressively finer classification of the enzyme.

For example, the tripeptide aminopeptidases have the code "EC 3.4.11.4", whose components indicate the following groups of enzymes:

EC 3 enzymes are hydrolase
Hydrolase

In biochemistry, a hydrolase is an enzyme that catalyzes the hydrolysis of a chemical bond. For example, an enzyme that catalyzed the following reaction is a hydrolase:...
s (enzymes that use water
Water

Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or States of matter, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam....
to break up some other molecule)
EC 3.4 are hydrolases that act on peptide bond
Peptide bond

A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amine group of the other molecule, thereby releasing a molecule of water ....
s
EC 3.4.11 are those hydrolases that cleave off the amino-terminal amino acid
Amino acid

In chemistry, an amino acid is a molecule containing both amine and carboxyl functional groups. These molecules are particularly important in biochemistry, where this term refers to alpha-amino acids with the general formula H2NCHRCOOH, where R is an organic substituent....
from a polypeptide
EC 3.4.11.4 are those that cleave off the amino-terminal end from a tripeptide
Tripeptide

A tripeptide is a peptide consisting of three amino acids joined by peptide bonds.Examples of tripeptides are:*Glutathione is an antioxidant, protecting cells from toxins such as free radicals....

Top level codes

Top-level EC numbers
Group	Reaction catalyzed	Typical reaction	Enzyme example(s) with trivial name
EC 1 List of EC numbers (EC 1) This list contains a list of EC numbers for the first group, EC 1, oxidoreducatases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.... Oxidoreductase Oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another .... s	To catalyze oxidation/reduction reactions; transfer of H and O atoms or electron Electron The electron is a subatomic particle that carries a negative electric charge. It has elementary particle and is believed to be a point particle.... s from one substance to another	AH + B ? A + BH (reduced) A + O ? AO (oxidized)	Dehydrogenase Dehydrogenase A dehydrogenase is an enzyme that oxidizes a substrate by transferring one or more hydrides to an acceptor, usually Nicotinamide adenine dinucleotide/NADP or a flavin coenzyme such as FAD or FMN.... , oxidase Oxidase An oxidase is any enzyme that catalyst an redox reaction involving molecular oxygen as the electron acceptor. In these reactions, oxygen is reduced to water or hydrogen peroxide ....
EC 2 List of EC numbers (EC 2) This list contains a list of EC numbers for the second group, EC 2, transferases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.... Transferase Transferase In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group from one molecule to another . For example, an enzyme that catalyzed this reaction would be a transferase:... s	Transfer of a functional group Functional group In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.... from one substance to another. The group may be methyl-, acyl-, amino- or phosphate group	AB + C ? A + BC	Transaminase Transaminase In biochemistry, a transaminase or an aminotransferase is an enzyme that catalyzes a type of reaction between an amino acid and an alpha-keto acid.... , kinase Kinase In chemistry and biochemistry, a kinase, alternatively known as a phosphotransferase, is a type of enzyme that transfers phosphate groups from High-energy phosphate donor molecules, such as adenosine triphosphate, to specific target molecules ; the process is termed phosphorylation ...
EC 3 List of EC numbers (EC 3) This list contains a list of EC numbers for the third group, EC 3, hydrolases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.... Hydrolase Hydrolase In biochemistry, a hydrolase is an enzyme that catalyzes the hydrolysis of a chemical bond. For example, an enzyme that catalyzed the following reaction is a hydrolase:... s	Formation of two products from a substrate by hydrolysis Hydrolysis Hydrolysis is a chemical reaction during which one or more water are split into hydrogen and hydroxide ions which may go on to participate in further reactions....	AB + H₂O ? AOH + BH	Lipase Lipase A lipase is a water-soluble enzyme that catalyzes the hydrolysis of ester chemical bond in water?insoluble, lipid substrates. Lipases thus comprise a subclass of the esterases.... , amylase Amylase Amylase is an enzyme that breaks starch down into sugar. Amylase is present in human saliva, where it begins the chemical process of digestion.... , peptidase
EC 4 List of EC numbers (EC 4) This list contains a list of EC numbers for the fourth group, EC 4, lyases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.... Lyase Lyase In biochemistry, a lyase is an enzyme that catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure.... s	Non-hydrolytic addition or removal of groups from substrates. C-C, C-N, C-O or C-S bonds may be cleaved	RCOCOOH ? RCOH + CO₂	Decarboxylase
EC 5 List of EC numbers (EC 5) This list contains a list of EC numbers for the fifth group, EC 5, isomerases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.... Isomerase Isomerase In biochemistry, an isomerase is an enzyme that catalyzes the structural rearrangement of isomers. Isomerases thus catalyze reactions of the form... s	Intramolecule rearrangement, i.e. isomerization Isomer In chemistry, isomers are compounds with the same molecular formula but different structural formulae. Isomers do not necessarily share similar properties unless they also have the same functional groups.... changes within a single molecule	AB ? BA	Isomerase Isomerase In biochemistry, an isomerase is an enzyme that catalyzes the structural rearrangement of isomers. Isomerases thus catalyze reactions of the form... , mutase Mutase An enzyme that catalyzes the shifting of a functional group from one position to another within the same molecule. Examples of this are bisphosphoglycerate mutase, which appears in red blood cells and phosphoglycerate mutase which acts in glycolysis....
EC 6 List of EC numbers (EC 6) This list contains a list of EC numbers for the sixth group, EC 6, ligases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.... Ligase Ligase In biochemistry, a ligase is an enzyme that can catalyse the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis of a small chemical group pendant to one of the larger molecules.... s	Join together two molecules by synthesis of new C-O, C-S, C-N or C-C bonds Covalent bond A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, or between atoms and other covalent bonds.... with simultaneous breakdown of ATP Adenosine triphosphate This article is about the chemical used by cells as an energy carrier. For other uses, see ATP .Adenosine-5'-triphosphate is a multifunctional nucleotide, and plays an important role in cell biology as a coenzyme that is the "molecule unit of currency" of intracellular energy transfer....	X + Y+ ATP ? XY + ADP + Pi	Synthetase

History

The enzyme nomenclature scheme was developed starting in 1955, when the International Congress of Biochemistry in Brussels

Brussels

Brussels , officially the Brussels Capital-Region, is the de facto capital city of the European Union and the largest urban area in Belgium....
set up an Enzyme Commission.

The first version was published in 1961.

The current sixth edition, published by the International Union of Biochemistry and Molecular Biology

International Union of Biochemistry and Molecular Biology

The International Union of Biochemistry and Molecular Biology is an international non-governmental organisation concerned with biochemistry and molecular biology....
in 1992, contains 3196 different enzymes.

External links

— by ExPASy
ExPASy

The ExPASy is a proteomics server of the Swiss Institute of Bioinformatics which analyzes protein sequences and structures and two-dimensional gel electrophoresis ....
— by BRENDA
BRENDA

BRENDA is an enzyme information system representing one of the most comprehensive enzyme repositories....

EC number

Format of number

Top level codes

History

See also

External links