Isolation and characterization of the gene coding for human cytidine deaminase

The human gene coding for cytidine deaminase (CD), the enzyme which catalyz es the deamination of cytidine and deoxycytidine to uridine and deoxyuridin e, was isolated and structurally characterized. CD is a single copy gene wi th a length of 31 kb and consists of four exons. Exon-intron junctions do n ot bracket functional domains of the encoded protein as the boundary betwee n exons 2 and 3 interrupts the catalytically important zinc-finger domain, which is well conserved along phylogenesis. 5'-RACE and RNase mapping exper iments identify one major and multiple other minor transcription initiation sites, which are present in placenta as well as in the myeloid cell lines, HL-60 and U937. The 5'-flanking region of the gene contains an orientation -dependent functional promoter and is characterized by the presence of seve ral potential sites for the binding of known transcriptional factors. (C) 1 998 Elsevier Science B.V. All rights reserved.