Structural and functional analysis of the murine adenosine deaminase gene.

We describe the structural and functional analysis of cosmid clones that span the entire murine adenosine deaminase gene. Functional analysis indicated that these clones are capable of encoding murine adenosine deaminase activity when introduced into human cell lines. Structural analysis revealed that the gene consists of 12 exons distributed over approximately 25 kb. The exact size of each exon and the sequence of each exon/intron junction were determined. The results show that the 1056-nucleotide open reading frame for adenosine deaminase extends from exon 1 to exon 11, and that exon 12 contains untranslated sequences only. During the course of these investigations, we discovered that a gene encoding an abundant 1.3-kb polyadenylated transcript overlaps the 3' end of the murine adenosine deaminase gene and is transcribed from the opposite strand.