A Novel Heterozygous Missense Mutation in GNAT1 Leads to Autosomal Dominant Riggs Type of Congenital Stationary Night Blindness

Figure 4

3D-model of normal and mutant GNAT1 interacting with GTPγS. The three-dimensional structure of (a) the GNAT1 wild-type; (b) the previously reported autosomal recessive CSNB mutant, p. Asp129Gly [15]; and the three autosomal dominant CSNB mutants: (c) p.Gly38Asp [5]; (d) p.Gln200Glu [14]; and (e) p.Ile52Asn. All GNAT1 variants are colored red and marked with a red arrow. The GTP-binding regions are colored in orange and GTP is colored in green. The novel autosomal dominant CSNB variant, p.Ile52Asn, does not affect the GTP-binding domain (in orange), while the two autosomal dominant CSNB variants, previously reported, p.Gly38Asp and p.Gln200Glu, are located in the GTP-binding domain (orange) and thus are predicted to affect the interaction with GTPγS (in green). A close-up of GTP-binding site was done for each construction, normal (a′) and GNAT1 mutants (b′, c′, d′, and e′).