Crystal and molecular structure of the dimer of variable domains of the Bence-Jones protein ROY

• Published in: Journal of molecular biology Vol. 116; no. 1; pp. 73 - 79
• Main Authors: Colman, P.M., Schramm, H.J., Guss, J.M.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.10.1977
• Subjects: Bence Jones Protein; Crystallography; Immunoglobulin Variable Region; Models, Chemical; Protein Conformation
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/0022-2836(77)90119-X

The crystal and molecular structure of the dimer of variable domains of the Bence-Jones protein ROY has been determined by Patterson function search procedures, using the known structure of the protein REI. The structure has been partially refined at 3.0 Å resolution to a crystallographic R-factor value of 0.33. One of the 18 residues differentiating ROY from REI is the substitution of Tyr96 for Leu96, a substitution which makes the combining site of the ROY dimer larger. Substantial movement of Tyr49 suggests that point substitutions in the hypervariable segments may affect the conformation of neighbouring residues in the antigen-combining site, possibly producing differences in specificity larger than might otherwise be expected.