1E7N
The N-terminal domain of beta-B2-crystallin resembles the putative ancestral homodimer
Summary for 1E7N
| Entry DOI | 10.2210/pdb1e7n/pdb |
| Descriptor | BETA-CRYSTALLIN B2 (2 entities in total) |
| Functional Keywords | structural protein, eye lens protein, domain interactions, 2-fold symmetry |
| Biological source | MUS MUSCULUS (HOUSE MOUSE) |
| Total number of polymer chains | 2 |
| Total formula weight | 23822.25 |
| Authors | Clout, N.J.,Basak, A.,Wieligmann, K.,Bateman, O.A.,Jaenicke, R.,Slingsby, C. (deposition date: 2000-08-31, release date: 2000-10-05, Last modification date: 2024-05-08) |
| Primary citation | Clout, N.J.,Basak, A.,Wieligmann, K.,Bateman, O.A.,Jaenicke, R.,Slingsby, C. The N-Terminal Domain of Betab2-Crystallin Resembles the Putative Ancestral Homodimer. J.Mol.Biol., 304:253-, 2000 Cited by PubMed Abstract: betagamma-crystallins from the eye lens are proteins consisting of two similar domains joined by a short linker. All three-dimensional structures of native proteins solved so far reveal similar pseudo-2-fold pairing of the domains reflecting their presumed ancient origin from a single-domain homodimer. However, studies of engineered single domains of members of the betagamma-crystallin superfamily have not revealed a prototype ancestral solution homodimer. Here we report the 2.35 A X-ray structure of the homodimer of the N-terminal domain of rat betaB2-crystallin (betaB2-N). The two identical domains pair in a symmetrical manner very similar to that observed in native betagamma-crystallins, where N and C-terminal domains (which share approximately 35% sequence identity) are related by a pseudo-2-fold axis. betaB2-N thus resembles the ancestral prototype of the betagamma-crystallin superfamily as it self-associates in solution to form a dimer with an essentially identical domain interface as that between the N and C domains in betagamma-crystallins, but without the benefit of a covalent linker. The structure provides further evidence for the role of two-domain pairing in stabilising the protomer fold. These results support the view that the betagamma-crystallin superfamily has evolved by a series of gene duplication and fusion events from a single-domain ancestor capable of forming homodimers. PubMed: 11090271DOI: 10.1006/JMBI.2000.4197 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.35 Å) |
Structure validation
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