TdT Antibody / DNA nucleotidylexotransferase

Terminal Deoxynucleotidyl Transferase, also known as Terminal transferase, is a unique DNA polymerase that without template direction catalyzes the addition of deoxyribonucleotides onto the 3-prime-hydroxyl end of DNA primers. Its gene is mapped to the region 10q23-q24. And TdT cDNA contains an open reading frame of 1,530 basepairs corresponding to a protein containing 510 amino acids. TdT may be responsible for inserting nucleotides (N regions) at the V (H) -D and D-J (H) junctions of immunoglobulin genes. The enzyme is present in immature thymocytes, some bone marrow cells, transformed pre-B and pre-T cell lines, and leukemia cells. Additionally, TdT catalyses the addition of nucleotides to the 3' terminus of a DNA molecule. Unlike most DNA polymerases it does not require a template. The preferred substrate of this enzyme is a 3'-overhang, but it can also add nucleotides to blunt or recessed 3' ends. Cobalt is a necessary cofactor.