terminal deoxynucleotidyltransferase (terminal addition enzyme, terminal deoxynucleotidyltransferase, terminal transferase, DNTT, TDT)

Function

• template-independent DNA polymerase which catalyzes the random addition of deoxynucleoside 5'-triphosphate to the 3'-end of a DNA initiator
• one of the in vivo functions of this enzyme is the addition of nucleotides at the junction (N region) of rearranged Ig heavy chain & T-cell receptor gene segments during maturation of B-cells & T-cells
• interacts with PRP19 & DNTTIP1
• forms a ternary complex with DNTTIP2 & core histone, released from DNTTIP2/core histone complex by PCNA

deoxynucleoside triphosphate + DNA(n) <--> diphosphate + DNA(n+1)

Cofactor: Mg+2

Structure

• belongs to the DNA polymerase type-X family
• contains 1 BRCT domain

Compartment

nucleus

Pathology

• very high levels of enzyme activity have been detected in certain acute leukemic cells

More general terms

• DNA nucleotidylexotransferase

Database

• UniProt: http://www.uniprot.org/uniprot/P04053.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1791
• OMIM: https://mirror.omim.org/entry/187410