Wenk, Martina and Mayr, Eva-Maria (1998) Myxococcus xanthus spore coat protein S, a stress-induced member of the beta gamma-crystallin superfamily, gains stability from binding of calcium ions. EUROPEAN JOURNAL OF BIOCHEMISTRY, 255 (3). pp. 604-610. ISSN 0014-2956
Full text not available from this repository.Abstract
Protein S, a calcium-binding spore coat protein from the soil bacterium Myxococcus xanthus, belongs to a group of structurally related proteins, the beta gamma-crystallin superfamily. Common features of this protein family are the Greek-key structural motif or crystallin fold, and the fact that all members are extremely stable long term. To investigate the correlation between the stability and Greek-key topology, protein S was cloned, expressed in Escherichia coli and purified to homogeneity. Ca2+ binding influences the native tertiary structure of protein S, whereas the secondary structure remains unaffected as shown by spectroscopic methods. Ca2+ ions enhance the conformational stability of protein S significantly. The midpoints of urea and guanidinium chloride-induced transitions show a difference of 1.4 M and 0.5 M denaturant, respectively, in the absence and in the presence of calcium. An equilibrium intermediate indicating independent domain folding can be detected at pH 2. In addition, thermal denaturation shows a clear deviation from the two-state model of folding, again with a strong stabilisation by Ca2+ ions. Temperature and denaturant-induced equilibrium transitions are fully reversible. Our data implicate a different strategy for achieving the high stability required for the biological function compared with the structurally related lens crystallins.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | X-RAY-ANALYSIS; EYE-LENS; RNA-POLYMERASE; CLONED GENES; VERTEBRATE; EXPRESSION; EVOLUTION; BETA-B2-CRYSTALLIN; PEPTIDE; PACKING; Greek-key topology; beta gamma-crystallins; long-term stability; protein stability; ligand binding |
| 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: | 23 Feb 2023 09:43 |
| Last Modified: | 23 Feb 2023 09:43 |
| URI: | https://pred.uni-regensburg.de/id/eprint/49623 |
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