Identification of amino-acid polymorphism within the leucine zipper motif of mouse transcription factor A1.

Mouse transcription factor A1 (A1) is a mouse homologue of human E47, a ubiquitously expressed DNA-binding protein which contains a basic region, helix-loop-helix (HLH) and leucine zipper (LZ) motifs [Walker et al., Nucleic Acids Res. 18 (1990) 1159-1166]. Analyses of the nucleotide (nt) sequences of A1 cDNAs isolated from various mouse strains revealed amino acid (aa) polymorphism in the highly conserved region within the LZ motif. Interestingly, the location and pattern of aa deletions are identical to those previously described for the aa polymorphism within the human counterpart, E47 (E12) [Kamps et al., Cell 60 (1990) 547-555].