Ligase


Ligase

In biochemistry, a ligase (from the Latin verb "ligāre" — "to bind" or "to glue together") is an enzyme that can catalyse the joining of the sugar phosphate backbones of Okazaki fragments of DNA. Generally ligase catalyses the following reaction:

:Ab + C → A–C + b

or sometimes

:Ab + cD → A–D + b + c

where the lower case letters signify the small, pendant groups.

Nomenclature

The common names of ligase enzymes often include the word "ligase", such as DNA ligase, an enzyme commonly used in molecular biology laboratories to join together DNA fragments. Other common names for ligases include synthetase, because they are used to synthesize new molecules, or carboxylase when they are used to add carbon dioxide to a molecule.

Note that "synthetase" should not be confused with synthases, as synthases do not use energy from nucleoside triphosphates (such as ATP, GTP, CTP, TTP and UTP) and belong to the lyase group, while ligases do use nucleoside triphosphates.

Classification

Ligases are classified as EC 6 in the EC number classification of enzymes. Ligases can be further classified into six subclasses:
* includes ligases used to form carbon-oxygen bonds
* includes ligases used to form carbon-sulfur bonds
* includes ligases used to form carbon-nitrogen bonds (including argininosuccinate synthetase)
* includes ligases used to form carbon-carbon bonds
* includes ligases used to form phosphoric ester bonds
* includes ligases used to form nitrogen-metal bondsThis is used for Recombinant DNA Tencholgy

ee also

*DNA ligase

References

* [http://www.chem.qmul.ac.uk/iubmb/enzyme/EC6/intro.html EC 6 Introduction] from the Department of Chemistry at Queen Mary, University of London


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • ligase — [ ligaz ] n. f. • 1981; mot angl.; cf. ligand ♦ Biochim. Enzyme permettant l union de deux molécules avec rupture d une liaison à haut potentiel énergétique. A. D. N. ligase : enzyme catalysant l union de deux fragments d A. D. N. ● ligase nom… …   Encyclopédie Universelle

  • ligase — n. (Biochem.) An enzyme which catalyzes creation of a covalent bond between two substrates, resulting in a larger product which is a combination of the two starting materials; especially, {DNA ligase}, an enzyme which creates a phosphate bond… …   The Collaborative International Dictionary of English

  • ligase — [lī′gās΄, lī′gāz΄] n. any of a class of enzymes that act as catalysts in chemical reactions in which molecules are linked together, as in the synthesis and repair of DNA or in the formation of recombinant DNA …   English World dictionary

  • Ligase — En biochimie, une ligase est une enzyme qui catalyse la jonction de deux molécules (en anglais ligation) par de nouvelles liaisons covalentes avec hydrolyse concomitante de l ATP ou d autres molécules similaires. Nomenclature le nom courant des… …   Wikipédia en Français

  • Ligase — Ligasen (v. lat. ligare verbinden , verketten ) sind Enzyme, die das Verknüpfen zweier Moleküle durch eine chemische Bindung katalysieren. Dazu benötigen sie Energie, die aus der Spaltung energiereicher Nukleosidtriphosphate (NTP) stammt. Dabei… …   Deutsch Wikipedia

  • ligase — /luy gays, gayz/, n. Biochem. any of a class of enzymes that catalyze the joining of two molecules by formation of a covalent bond accompanied by the hydrolysis of ATP. [1961; < L lig(are) to tie, bind + ASE] * * * ▪ biochemistry also called… …   Universalium

  • ligase — ligazė statusas T sritis chemija apibrėžtis Fermentas, katalizuojantis kondensacijos (sintezės) reakcijas dalyvaujant didžiaenergiams junginiams. atitikmenys: angl. ligase; synthetase rus. лигаза; синтетаза ryšiai: sinonimas – sintetazė …   Chemijos terminų aiškinamasis žodynas

  • ligase — ligazė statusas T sritis augalininkystė apibrėžtis Fermentas, katalizuojantis sintezės reakcijas, dalyvaujant didžiaenergiams junginiams. atitikmenys: angl. ligase; synthetase rus. лигаза; синтетаза …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • ligase — See: DNA ligase …   Glossary of Biotechnology

  • ligase — noun Etymology: International Scientific Vocabulary lig (from Latin ligare) + ase Date: 1961 synthetase …   New Collegiate Dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.