Abstract
Calpain is a Ca2+-activated, heterodimeric cysteine protease consisting of a large catalytic subunit and a small regulatory subunit. Dysregulation of this enzyme is involved in a range of pathological conditions such as cancer, Alzheimer's disease and rheumatoid arthritis, and thus calpain I is a drug target with potential therapeutic applications. Difficulty in the production of this enzyme has hindered structural and functional investigations in the past, although heterodimeric calpain I can be generated by Escherichia coli expression in low yield. Here, an unexpected structure discovered during crystallization trials of heterodimeric calpain I (CAPN1C115S + CAPNS1ΔGR) is reported. A novel co-crystal structure of the PEF(S) domain from the dissociated regulatory small subunit of calpain I and the RNA-binding chaperone Hfq, which was likely to be overproduced as a stress response to the recombinant expression conditions, was obtained, providing unexpected insight in the chaperone function of Hfq.
Original language | English |
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Pages (from-to) | 81-85 |
Number of pages | 5 |
Journal | Acta Crystallographica. Section F: Structural Biology and Crystallization Communications |
Volume | 76 |
Issue number | Pt 2 |
DOIs | |
Publication status | Published - 1 Feb 2020 |
Keywords
- Calpain/chemistry
- Crystallography, X-Ray
- Host Factor 1 Protein/chemistry
- Humans
- Models, Molecular
- Molecular Chaperones/chemistry
- Protein Binding
- Protein Conformation
- Protein Domains
- Protein Multimerization