Werten, Paul J. L. and Carver, John A. and Jaenicke, Rainer and De Jong, Wilfried W. (1996) The elusive role of the N-terminal extension of beta A3- and beta A1-crystallin. PROTEIN ENGINEERING, 9 (11). pp. 1021-1028. ISSN 0269-2139
Full text not available from this repository.Abstract
beta-Crystallins are structural lens proteins with a conserved two-domain structure and variable N- and C-terminal extensions. These extensions are assumed to be involved in quaternary interactions within the beta-crystallin oligomers or with other lens proteins. Therefore, the production of beta A3- and beta A1-crystallin from the single beta A3/A1 mRNA by dual translation initiation is of interest. These crystallins are identical, except that beta A1 has a much shorter N-terminal extension than beta A3. This rare mechanism has been conserved for over 250 million years during the evolution of the beta A3/A1 gene, suggesting that the generation of different N-terminal extensions confers a selective advantage. We therefore compared the stability and association behaviour of recombinant beta A3- and beta A1-crystallin. Both proteins are equally stable in urea- and pH-induced denaturation experiments. Gel filtration and analytical ultracentrifugation established that beta A3 and beta A1 both form homodimers. In the water-soluble proteins of bovine lens, beta A3 and beta A1 are present in the same molecular weight fractions, indicating that they oligomerize equally with other beta-crystallins. H-1-NMR spectroscopy showed that residues Met1 to Asn22 of the N-terminal extension of beta A3 have great flexibility and are solvent exposed, excluding them from protein interactions in the homodimer. These results indicate that the different N-terminal extensions of beta A3 and beta A1 do not affect their homo- or heteromeric interactions.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | X-RAY-ANALYSIS; MONOMERIC GAMMA-CRYSTALLIN; CALF EYE LENS; H-1-NMR SPECTROSCOPY; LIMITED PROTEOLYSIS; SEQUENCE-ANALYSIS; NMR-SPECTROSCOPY; MESSENGER-RNA; II-CRYSTALLIN; BP CHAIN; beta-crystallin; lens proteins; protein association; protein evolution; sequence extensions |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 21 Jun 2023 10:07 |
| Last Modified: | 21 Jun 2023 10:07 |
| URI: | https://pred.uni-regensburg.de/id/eprint/51399 |
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