Circular permutation of betaB2-crystallin changes the hierarchy of domain assembly.
The betagamma-crystallins form a superfamily of eye lens proteins comprised of multiple Greek motifs that are symmetrically organized into domains and higher assemblies. In the betaB2-crystallin dimer each polypeptide folds into two similar domains that are related to monomeric gamma-crystallin by domain swapping. The crystal structure of the circularly permuted two-domain betaB2 polypeptide shows that permutation converts intermolecular domain pairing into intramolecular pairing. However, the dimeric permuted protein is, in fact, half a native tetramer. This result shows how the sequential order of domains in multi-domain proteins can affect quaternary domain assembly.
Wright
G
G
Birkbeck College, Department of Crystallography, London, United Kingdom.
Basak
A K
AK
Wieligmann
K
K
Mayr
E M
EM
Slingsby
C
C
D000818:Animals; D003459:Crystallins / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding; D051381:Rats
D003459:Crystallins; D046911:Macromolecular Substances