Open AccessCrystal and Molecular Structure of a Dimer Composed of the Variable Portions of the Bence‐Jones Protein REI
Author(s) -
Epp Otto,
Colman Peter,
Fehlhammer Heinz,
Bode Wolfram,
Huber Robert,
Schiffer Marianne,
Palm Walter
Publication year - 1974
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1974.tb03576.x
Subject(s) - bence jones protein , dimer , crystallography , chemistry , monomer , beta sheet , crystal structure , stereochemistry , immunoglobulin light chain , hydrogen bond , protein structure , molecule , biochemistry , biology , antibody , genetics , organic chemistry , polymer
The structure of the variable part of a χ‐type Bence‐Jones protein RE1 has been determined at a resolution of 0.28 nm. It forms a dimer in the crystal related by a local diad, held together by hydrogen bonding interactions of residues Tyr‐36, Gln‐38, Ala‐43, Pro‐44, Tyr‐87, Gln‐89 and Phe‐98, which are largely conserved in light chains. The structure consists of two hydrogen‐bonded sheets covering a hydrophobic interior made up of mostly conserved amino‐acid side chains. Approximately 50% of the residues form β‐pleated sheets. Several of the pleated sheet strands are connected by hair‐pin bends, which contain glycine residues conserved in most light chains. The arrangement of the hypervariable segments especially in comparison with the Fab structure suggests that the V dimers form a primitive antibody. The folding of the poly‐peptide chain and the spatial relationship of the two monomers appear to be the same as in the λ‐type Bence‐Jones protein dimer and the Fab fragment.