Effect of mutations on the structure of GFI1. (A) Schematic structure of zing fingers 5 and 6 of Gfi1 and localization of the most common mutations found in families with SCN. The affected amino acids are indicated. (B) Consequence of the N382S mutation on the tertiary structure of zinc finger 5 in the human GFI1 protein: in the wild-type form, Asn-382 forms 2 hydrogen bonds with the DNA strand, which is lost in the GFI1 variant carrying the N382S mutation (red circle).