- This article is about the Enzyme Commission codes. For the European Commission system for coding chemicals, see EC-No. The terms EC-No and EC# refer to the seven-digit code (sometimes called the EC number) that has been allocated by the Commission of the European Communities
The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. There are many different numbering schemes for assigning Nominal numbers to entities Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins 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 Catalysis is the process in which the rate of a Chemical reaction is increased 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. If different enzymes (for instance from different organisms) catalyze the same reaction, then they receive the same EC number. By contrast, UniProt identifiers uniquely specify a protein by its amino acid sequence. UniProt is the uni versal prot ein resource a central repository of Protein data created by combining Swiss-Prot, TrEMBL [1]
Contents |
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 hydrolases (enzymes that use water to break up some other molecule)
- EC 3. In Biochemistry, a hydrolase is an Enzyme that catalyzes the Hydrolysis of a Chemical bond. Water is a common Chemical substance that is essential for the survival of all known forms of Life. 4 are hydrolases that act on peptide bonds
- EC 3. A peptide bond is a Chemical bond formed between two Molecules when the Carboxyl group of one molecule reacts with the 4. 11 are those hydrolases that cleave off the amino-terminal amino acid from a polypeptide
- EC 3. In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this Peptides (from the Greek πεπτίδια, "small digestibles" are short Polymers formed from the linking in a defined order of α- Amino 4. 11. 4 are those that cleave off the amino-terminal end from a tripeptide
Top level codes
| Group | Reaction catalyzed | Typical reaction | Enzyme example(s) with trivial name |
|---|---|---|---|
| EC 1 Oxidoreductases |
To catalyze oxidation/reduction reactions; transfer of H and O atoms or electrons from one substance to another | AH + B → A + BH (reduced) A + O → AO (oxidized) |
Dehydrogenase, oxidase |
| EC 2 Transferases |
Transfer of a functional group from one substance to another. A tripeptide is a Peptide consisting of three Amino acids joined by Peptide bonds Examples of tripeptides are Glutathione In Biochemistry, an oxidoreductase is an Enzyme that catalyzes the transfer of Electrons from one molecule (the reductant, also called the hydrogen Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J A dehydrogenase is an Enzyme that Oxidizes a substrate by transferring one or more Protons and a pair of electrons to an acceptor usually An oxidase is any Enzyme that catalyzes an oxidation/reduction reaction involving molecular Oxygen (O2 as the electron acceptor In Biochemistry, a transferase is an Enzyme that catalyzes the transfer of a Functional group (e In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions The group may be methyl-, acyl-, amino- or phosphate group | AB + C → A + BC | Transaminase, kinase |
| EC 3 Hydrolases |
Formation of two products from a substrate by hydrolysis | AB + H2O → AOH + BH | Lipase, amylase, peptidase |
| EC 4 Lyases |
Non-hydrolytic addition or removal of groups from substrates. In Biochemistry, a transaminase or an aminotransferase is an Enzyme that Catalyzes a type of reaction between an Amino acid and an In Chemistry and Biochemistry, a kinase, alternatively known as a phosphotransferase, is a type of Enzyme that transfers Phosphate In Biochemistry, a hydrolase is an Enzyme that catalyzes the Hydrolysis of a Chemical bond. Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions A lipase is a Water-soluble Enzyme that Catalyzes the Hydrolysis of Ester bonds in water–insoluble Lipid Amylase is an Enzyme that breaks Starch down into Sugar. Amylase is present in human Saliva, where it begins the chemical process A protease is any Enzyme that conducts Proteolysis, that is begins protein Catabolism by Hydrolysis of the Peptide bonds that link In Biochemistry, a lyase is an Enzyme that catalyzes the breaking of various Chemical bonds by means other than Hydrolysis and Oxidation C-C, C-N, C-O or C-S bonds may be cleaved | RCOCOOH → RCOH + CO2 | Decarboxylase |
| EC 5 Isomerases |
Intramolecule rearrangement, i. Carboxy-lyases, also known as decarboxylases, are carbon-carbon Lyases that add or remove a Carboxyl group from Organic compounds These In Biochemistry, an isomerase is an Enzyme that catalyses the structural rearrangement of Isomers Isomerases thus catalyze reactions of the form e. isomerization changes within a single molecule | AB → BA | Isomerase, mutase |
| EC 6 Ligases |
Join together two molecules by synthesis of new C-O, C-S, C-N or C-C bonds with simultaneous breakdown of ATP | 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 set up an Enzyme Commission. This article is about the chemical concept For "isomerism" of atomic nuclei see Nuclear isomer. In Biochemistry, an isomerase is an Enzyme that catalyses the structural rearrangement of Isomers Isomerases thus catalyze reactions of the form An Enzyme that catalyzes the shifting of a functional group from one position to another within the same molecule In Biochemistry, a ligase (from the Latin verb ligāre &mdash "to bind" or "to glue together" is an Enzyme that can catalyse Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy In Biochemistry, a ligase (from the Latin verb ligāre &mdash "to bind" or "to glue together" is an Enzyme that can catalyse Year 1955 ( MCMLV) was a Common year starting on Saturday (link displays the 1955 Gregorian calendar) Brussels (Bruxelles pronounced; Brussel pronounced) officially the Brussels Capital-Region, is
The first version was published in 1961. Year 1961 ( MCMLXI) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar.
The current sixth edition, published by the International Union of Biochemistry and Molecular Biology in 1992, contains 3196 different enzymes. The International Union of Biochemistry and Molecular Biology ( IUBMB) is an international Non-governmental organisation concerned with Biochemistry and Year 1992 ( MCMXCII) was a Leap year starting on Wednesday (link will display full 1992 Gregorian calendar)
References
- ^ ENZYME (Enzyme nomenclature database). ExPASy. Retrieved on 2006-03-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1489 - The Queen of Cyprus, Catherine Cornaro, sells her kingdom to Venice.
- ^ Moss, G. P. . Recommendations of the Nomenclature Committee. International Union of Biochemistry and Molecular Biology on the Nomenclature and Classification of Enzymes by the Reactions they Catalyse. Retrieved on 2006-03-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1489 - The Queen of Cyprus, Catherine Cornaro, sells her kingdom to Venice.
See also
- TC number (classification of membrane transport proteins)
- List of enzymes
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