Protein
DNA nucleotidylexotransferase
Function
Isoform TDT-L: 3'-to-5' DNA exonuclease. Involved in the generation of diversity in the antigen-binding region of immunoglobulin heavy and light chains and T-cell receptors during B-and T-cell development. Acts on single-stranded and double-stranded DNA with 3' or 5' extensions, but not on double-stranded DNA with blunt ends. Attenuates not only isoform TDT-S-catalyzed N addition, but also P (palindromic) addition in coding joins (PubMed:11938351). Lacks terminal transferase activity (PubMed:11136823, PubMed:7556063).
Similarity
Belongs to the DNA polymerase type-X family.
Sequence
MDPLQAVHLGPRKKRPRQLGTPVASTPYDIRFRDLVLFILEKKMGTTRRAFLMELARRKGFRVENELSDSVTHIVAENNSGSDVLEWLQLQNIKASSELELLDISWLIECMGAGKPVEMMGRHQLVVNRNSSPSPVPGSQNVPAPAVKKISQYACQRRTTLNNYNQLFTDALDILAENDELRENEGSCLAFMRASSVLKSLPFPITSMKDTEGIPCLGDKVKSIIEGIIEDGESSEAKAVLNDERYKSFKLFTSVFGVGLKTAEKWFRMGFRTLSKIQSDKSLRFTQMQKAGFLYYEDLVSCVNRPEAEAVSMLVKEAVVTFLPDALVTMTGGFRRGKMTGHDVDFLITSPEATEDEEQQLLHKVTDFWKQQGLLLYCDILESTFEKFKQPSRKVDALDHFQKCFLILKLDHGRVHSEKSGQQEGKGWKAIRVDLVMCPYDRRAFALLGWTGSRQFERDLRRYATHERKMMLDNHALYDRTKRVFLEAESEEEIFAHLGLDYIEPWERNA