Cellular retinaldehyde-binding protein (CRALBP) is essential for mammalian vision by routing 11-cis-retinoids for the conversion of photo-bleached opsin molecules into photosensitive visual pigments. The R234W missense mutation within the human gene encoding CRALBP compromises visual pigment regeneration and is associated with Bothnia type retinitis pigmentosa (RP).
The picture shows (A) a close-up of the crystal structures of human CRALBP and of the Bothnia mutant R234W revealing a domino-like mechanism of impaired 11-cis-retinal release and (B) Bothnia RP associated symptoms of progressive loss in the peripheral visual field in daylight, eventually leading to blindness after several decades.

This work was carried out in the group of PD Dr. Achim Stocker by Xiaoqin He and Joel Lobsiger.

References:

• Xiaoqin He, Joel Lobsiger and Achim Stocker;
  "Bothnia dystrophy is caused by domino-like rearrangements in cellular retinaldehyde-binding protein mutant R234W"
  Proc. Natl. Acad. Sci. USA, 106, 18545-18550, (2009); doi:10.1073/pnas.0907454106.