Gain, Loss and Divergence in Primate Zinc-Finger Genes: A Rich Resource for Evolution of Gene Regulatory Differences between Species
A. Both proteins contain a KRAB-A, a KRAB-B, and a polydactyl ZNF domain. The last two ZNF motifs are not functional in both species due to mutations of the Histidine residues preventing the correct folding of the binding domain. The first two ZNF motifs of the chimpanzee gene are not included in the protein. Homologous ZNF motifs are indicated by green lines. The first three, the 6th to 10th, as well as the 16th ZNF motif are deleted in chimpanzee ZNF780B. The human ZNF780B protein is characterized by a human-specific amino acid at position 6 in the 17th ZNF motif, indicated by a star. B: Binding motifs for human and chimpanzee ZNF780B as predicted by the tool developed by Kaplan and colleagues (28). Corresponding stretches of the binding motif and ZNF domains are indicated by numbers, the star, and green lines, respectively.