FIGURE 1.

Detailed views of the experimental three-dimensional structure of human Cernunnos (Protein Data Bank 2R9A (6)). This figure shows the positions of the amino acids of four groups, as selected for this point mutational analysis. Group 1 corresponds to two sets of conserved amino acids, which were predicted to cluster at the surface of the globular head domain (with Leu⁶¹, Phe¹¹⁷, and Trp¹¹⁹ (green) actually buried in the experimental structure). Group 2 corresponds to a set of amino acids predicted to be included in the interface between the head and stalk domains. Group 3 includes conserved amino acids in the stalk domain (L4 binding region of X4), whereas group 4 is formed by amino acids, which are associated with naturally occurring mutations.