Norledge, BV and Trinkl, S and Jaenicke, R and Slingsby, C (1997) The X-ray structure of a mutant eye lens beta B2-crystallin with truncated sequence extensions. PROTEIN SCIENCE, 6 (8). pp. 1612-1620. ISSN 0961-8368,
Full text not available from this repository.Abstract
beta-Crystallins are oligomeric eye lens proteins that are related to monomeric gamma-crystallins by domain swapping: like gamma-crystallins. they are comprised of two similar domains but they differ in having long sequence extensions, beta B2. a major component of beta-crystallin oligomers, self-associates to a homodimer in solution. In two crystal structures of native beta B2. the protein is a 222-symmetric tetramer of eight domains. It has previously been shown that a mutant of rat beta B2-crystallin, in which the bulk of the N- and C-terminal sequence extensions has been deleted, assembles into dimers and tetramers. Here we present the 3.0 Angstrom resolution X-ray structure of the tetramer, beta B2 Delta NCl. The mutant tetramer has a very similar set of domain interactions to the native structure. However, the structures differ in the relative orientation of the two sets of four domains. The paired N- and C-terminal domain interface, which is at the heart of the dimer structure, is very similar to the native structure. However, the truncation of the C-terminal extension removes an important tryptophan residue, which prevents the extension from acting as a (non-covalent) linker as it does in native beta B2. There is a knock-on structural effect that removes a contact between extension and covalent linker, and this appears to cause a small twist in the linker that is amplified into a 20 degrees rotation between sets of paired domains.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | C-TERMINAL EXTENSIONS; BETA-CRYSTALLIN; GAMMA-CRYSTALLIN; EVOLUTION; PROTEINS; SYMMETRY; PACKING; CELL; beta B2-crystallin; domain interactions; extension; linker |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:31 |
| URI: | https://pred.uni-regensburg.de/id/eprint/50685 |
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