Isolation of putative promoter region for human terminal deoxynucleotidyltransferase gene.

We have isolated the genomic clone, which contained 5'-flanking region for human terminal deoxynucleotidyltransferase (TdT) gene, by screening Charon 4A library and determined its nucleotide sequence. Two transcription initiation sites (cap sites) were localized at 81 and 106 bp upstream from the third ATG codon which is translation initiation site, by primer extension analysis. Although neither typical TATA nor CAAT sequences were detected within 100 bp upstream region of the 5' cap site, a palindromic structure comprised of 28 bp was formed just upstream of the 5' cap site and double repeats of 5'-CTGGC sequence were found in its palindrom. The typical octamer of 5'-ATGCAAAT and three octamer-like sequences, which are involved in the transcription of lymphoid-specific genes, were detected at 212, 293, 347 and 770 bp upstream from the first cap site.