Protein crystal structure may help explain childhood blindness

摘要

Vision is made possible in vertebrates when light entering the retina transforms the visual pigment rhodopsin's chromophore from the cis to the trans isomer, activating retinal photoreceptors that relay an electrical signal to the brain. Continued sight relies on the RPE65 enzyme, which carries out reconversion of the chromophore to the light-sensitive cis isomer. Although the catalytic mechanism of the retinal enzyme is unknown, mutations in RPE65 are known to cause a form of hereditary childhood blindness called Leber congenital amau-rosis (LCA).