Human and mouse Krüppel-like (MOK2) orthologue genes encode two different zinc finger proteins

We have isolated the human homologue of Mok2 gene encoding a Krüppel-like protein. The identification of three cDNAs and genomic clones reveals that the human protein shows substantial structural differences with the mouse MOK2 protein. The mouse MOK2 protein is composed of seven tandem zinc-finger motifs with five additional amino acids at the COOH-terminal. This structural feature is also present at the end of the human MOK2 protein. The seven zinc-finger motifs show 94% identity between the two proteins. In addition, the human protein contains three additional zinc-finger motifs in tandem with the others and a nonfinger acidic domain of 173 amino acids at the NH2-terminal. The Southern analysis indicates that a single copy of these two genes is present in the 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 ancestor results in the loss of a potential transcription activator domain in mouse MOK2 protein.