Download citation
Download citation
link to html
Cellular retinol-binding proteins (CRBPs) I and II, which are members of the intracellular lipid-binding protein (iLBP) family, are retinoid chaperones that are responsible for the intracellular transport and delivery of both retinol and retinal. Although structures of retinol-bound CRBPI and CRBPII are known, no structure of a retinal-bound CRBP has been reported. In addition, the retinol-bound human CRBPII (hCRBPII) structure shows partial occupancy of a non­canonical conformation of retinol in the binding pocket. Here, the structure of retinal-bound hCRBPII and the structure of retinol-bound hCRBPII with retinol fully occupying the binding pocket are reported. It is further shown that the retinoid derivative seen in both the zebrafish CRBP and the hCRBPII structures is likely to be the product of flux-dependent and wavelength-dependent X-ray damage during data collection. The structures of retinoid-bound CRBPs are compared and contrasted, and rationales for the differences in binding affinities for retinal and retinol are provided.

Supporting information

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S1399004714023839/qh5018sup1.pdf
Supporting Information.

PDB references: hCRBPII, bound to retinol, 4qyn; 4qzt; 4qzu; bound to retinal, 4qyp


Follow Acta Cryst. D
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds