Munte, Claudia Elisabeth and Kreitner, Raphael and Rachel, Reinhard and Stetter, Karl O. and Kremer, Werner and Kalbitzer, Hans Robert (2025) Biophysical characterization and solution structure of the cannulae-forming protein CanA from the hyperthermophilic archaeon Pyrodictium abyssi. SCIENTIFIC REPORTS, 15 (1): 28563. ISSN 2045-2322,
Full text not available from this repository. (Request a copy)Abstract
CanA from Pyrodictium abyssi, the main constituent of the extracellular protein network of this archaeon, forms a hollow-fiber network in the presence of divalent ions. The polymerization of CanA induced by divalent ions is characterized by (at least) two processes with rate constants of 0.19 and 0.03 ms-1 at 298 K with a critical monomer concentration of 2.48 mu M. A non-polymerizing mutant, K1-CanA, was created, and the NMR solution structure could be determined by multidimensional NMR spectroscopy. It mainly consists of beta-pleated sheets and 2 small alpha-helices, arranged as beta 1 beta 2 beta 3 beta 4 alpha 1 beta 5 beta 6 alpha 2 beta 7 beta 8 beta 9 beta 10 beta 11 beta 12 beta 13. Of the 13 beta-strands, 8 form a non-canonical jellyroll class I fold. Several interaction sites for divalent ions could be identified by [1H, 15N]-SOFAST-HMQC spectroscopy in two main surface areas called BA1 and BA2, located at both ends of the jellyroll. The binding of divalent ions to the monomer induces significant local structural changes in these areas. In general, the affinities for Mg2+-ions to the sites in BA1 are smaller than those for Ca2+-ions. In contrast, in binding area BA2, Mg2+- and Ca2+-affinities are similar. The data suggest a conformational selection mechanism induced by ion binding as a first step in the polymerization process of CanA.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CALCIUM-BINDING; SECONDARY STRUCTURE; ACID; NOV; |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Dr. Hans Robert Kalbitzer Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Mikrobiologie (Archaeenzentrum) > Prof. Dr. Reinhard Rachel |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 16 Jun 2026 05:01 |
| Last Modified: | 16 Jun 2026 05:01 |
| URI: | https://pred.uni-regensburg.de/id/eprint/65948 |
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