1YTQ
Structure of Native Human Beta B2 Crystallin
Summary for 1YTQ
| Entry DOI | 10.2210/pdb1ytq/pdb |
| Related | 2BB2 |
| Descriptor | Beta crystallin B2 (2 entities in total) |
| Functional Keywords | crystallin, domain swapping, greek key, structural protein |
| Biological source | Homo sapiens (human) |
| Total number of polymer chains | 1 |
| Total formula weight | 23280.73 |
| Authors | Slingsby, C.,Smith, M.A.,Bateman, O.A. (deposition date: 2005-02-10, release date: 2006-01-31, Last modification date: 2024-03-13) |
| Primary citation | Smith, M.A.,Bateman, O.A.,Jaenicke, R.,Slingsby, C. Mutation of interfaces in domain-swapped human betaB2-crystallin Protein Sci., 16:615-625, 2007 Cited by PubMed Abstract: The superfamily of eye lens betagamma-crystallins is highly modularized, with Greek key motifs being used to form symmetric domains. Sequences of monomeric gamma-crystallins and oligomeric beta-crystallins fold into two domains that pair about a further conserved symmetric interface. Conservation of this assembly interface by domain swapping is the device adopted by family member betaB2-crystallin to form a solution dimer. However, the betaB1-crystallin solution dimer is formed from an interface used by the domain-swapped dimer to form a tetramer in the crystal lattice. Comparison of these two structures indicated an intriguing relationship between linker conformation, interface ion pair networks, and higher assembly. Here the X-ray structure of recombinant human betaB2-crystallin showed that domain swapping was determined by the sequence and not assembly conditions. The solution characteristics of mutants that were designed to alter an ion pair network at a higher assembly interface and a mutant that changed a proline showed they remained dimeric. X-ray crystallography showed that the dimeric mutants did not reverse domain swapping. Thus, the sequence of betaB2-crystallin appears well optimized for domain swapping. However, a charge-reversal mutation to the conserved domain-pairing interface showed drastic changes to solution behavior. It appears that the higher assembly of the betagamma-crystallin domains has exploited symmetry to create diversity while avoiding aggregation. These are desirable attributes for proteins that have to exist at very high concentration for a very long time. PubMed: 17327390DOI: 10.1110/ps.062659107 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
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