Crystallographic refinement of human serum retinol binding protein at 2Å resolution
Human serum retinol binding protein (RBP) in complex with retinol has been crystallographically refined to an R‐factor of 18.1% with 2Å resolution data. The protein topology results in an anti‐parallel β‐barrel that encapsulates the retinol ligand. A detailed description of the protein and the binding site is provided. Our structural work has helped to define a family of proteins, many of which are carrier proteins for smaller ligand molecules. We describe the structural basis for the conservation of sequence within the family. Copyright © 1990 Wiley‐Liss, Inc.