Characterization and crystallization of core streptavidin.
We have characterized a streptavidin product that had been reduced to a minimal size that still retained full biotin-binding activity. This core streptavidin is proteolyzed at both ends at points that correspond closely with the termini of hen egg white avidin. Core streptavidin is more soluble than is the parent molecule. We have grown three different types of crystals of core streptavidin. The symmetry properties of these crystals prove that the molecule is a tetramer organized in tetrahedral (D2) point symmetry. The crystallographic response to the interaction of biotin with core streptavidin indicates that some conformational change accompanies ligand binding. We are attempting to determine the three-dimensional structure of streptavidin and its complex with selenobiotin from these crystals of core streptavidin.
Pähler
A
A
Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032.
Hendrickson
W A
WA
Kolks
M A
MA
Argaraña
C E
CE
Cantor
C R
CR
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000302:isolation & purification; D002268:Carboxypeptidases; D003460:Crystallization; D046911:Macromolecular Substances; D011487:Protein Conformation; D019809:Streptavidin; D014961:X-Ray Diffraction
D001426:Bacterial Proteins; D046911:Macromolecular Substances; D019809:Streptavidin; D002268:Carboxypeptidases