Terminal deoxynucleotidyl transferase
3034920
189522272
2008-02-06T16:33:57Z
Mikael Häggström
2615838
direction
{{protein
|Name=deoxynucleotidyltransferase, terminal
|caption=
|image=
|width=
|HGNCid=2983
|Symbol=DNTT
|AltSymbols=
|EntrezGene=1791
|OMIM=187410
|RefSeq=NM_004088
|UniProt=P04053
|PDB=
|ECnumber=2.7.7.31
|Chromosome=10
|Arm=q
|Band=23
|LocusSupplementaryData=-q24
}}
'''Terminal Deoxynucleotidyl Transferase''', also known as '''TdT''' and '''terminal transferase''', is a specialized [[DNA polymerase]] expressed in immature, pre-B, pre-T [[lymphoid]] cells, and [[acute lymphoblastic leukemia]]/lymphoma cells. TdT adds N-nucleotides to the variable, diversity, and joining [[exon]]s during [[antibody gene recombination]].
TdT [[catalysis|catalyses]] the addition of [[nucleotide]]s to the [[DNA end|3' terminus]] of a [[DNA]] molecule. Unlike most DNA polymerases it does not require a template. The preferred substrate of this enzyme is a [[DNA end|3'-overhang]], but it can also add nucleotides to blunt or recessed 3' ends. [[Cobalt]] is a necessary [[cofactor]].
Terminal transferase has applications in [[molecular biology]]. It can be used in [[RACE]] to add nucleotides which can then be used as a template for a primer in subsequent [[PCR]]. It can also be used to add nucleotides labelled with [[radioactivity|radioactive]] [[isotope]]s.
Also used in the immunofluorescence assay for the diagnosis of acute lymphoblastic leukemia.
It is the main enzyme used in [[TUNEL assay]] ('''T'''erminal deoxynucleotidyl transferase d'''U'''TP '''N'''ick '''E'''nd '''L'''abeling) for the demonstration of [[apoptosis]].
== See also ==
*[[DNA]]
*[[DNA polymerase]]
==External links==
* {{MeshName|Terminal+Deoxyribonucleotidyltransferase}}
{{transferase-stub}}
{{Kinases}}
[[de:Desoxyribonukleotidyltransferase]]