Researchers at the University of California, Irvine have discovered profound similarities and surprising differences between humans and insects in the production of the critical light-absorbing molecule of the retina, 11-cis-retinal, also known as the “visual chromophore.” The findings deepen understanding of how mutations in the RPE65 enzyme cause retinal diseases, especially Leber congenital amaurosis, a devastating childhood blinding disease.
For the study, recently published online in the journal Nature Chemical Biology, the team used X-ray crystallography to study NinaB, a protein found in insects that functions similarly to the RPE65 protein found in humans. Both are crucial for synthesis of 11-cis-retinal, and their absence results in severe visual impairment.
Through their study of NinaB, the team was able to understand the structure of a previously unresolved region of RPE65.