HUMAN AND MOUSE KRUPPEL-LIKE (MOK2) ORTHOLOGUE GENES ENCODE 2 DIFFERENT ZINC-FINGER PROTEINS

We have isolated the human homologue of Mok2 gene encoding a Kruppel-l ike protein. The identification of three cDNAs and genomic clones reve als that the human protein shows substantial structural differences wi th the mouse MOK2 protein. The mouse MOK2 protein is composed of seven tandem zinc-finger motifs with five additional amino acids at the COO H-terminal. This structural feature is also present at the end of the human MOK2 protein. The seven zinc-finger motifs show 94% identity bet ween the two proteins. In addition, the human protein contains three a dditional zinc-finger motifs in tandem with the others and a nonfinger acidic domain of 173 amino acids at the NH2-terminal. The Southern an alysis indicates that a single copy of these two genes is present in t he genome. The human gene has been localized on chromosome 19 on band q13.2-q13.3. The comparison of human and mouse cDNA sequences reveals a strong identity in the sequences localized outside the seven highly conserved zinc-finger motifs. The divergence from their common ancesto r results in the loss of a potential transcription activator domain in mouse MOK2 protein.