Allosteric regulation of Csx1, a type IIIB-associated CARF domain ribonuclease by RNAs carrying a tetraadenylate tail
| Autor: | Guillermo Montoya, Blanca López-Méndez, Wenyuan Han, Saifu Pan, Qunxin She |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Rossmann fold RNA polyadenylation Archaeal Proteins Allosteric regulation Biology Ligands Sulfolobus 03 medical and health sciences Allosteric Regulation Protein Domains Endoribonucleases Genetics Ribonuclease RNA Messenger RNA Cleavage Nuclease Nucleic Acid Enzymes RNA Ligand (biochemistry) 030104 developmental biology Biochemistry Metals biology.protein Poly A Protein Binding |
| Zdroj: | Han, W, Pan, S, López-Méndez, B, Montoya, G & She, Q 2017, ' Allosteric regulation of Csx1, a type IIIB-associated CARF domain ribonuclease by RNAs carrying a tetraadenylate tail ', Nucleic Acids Research, vol. 45, no. 18, gkx726, pp. 10740-10750 . https://doi.org/10.1093/nar/gkx726 Nucleic Acids Research |
| DOI: | 10.1093/nar/gkx726 |
| Popis: | CRISPR–Cas systems protect prokaryotes against invading viruses and plasmids. The system is associated with a large number of Cas accessory proteins among which many contain a CARF (CRISPR-associated Rossmann fold) domain implicated in ligand binding and a HEPN (higher eukaryotes and prokaryotes nucleotide-binding) nuclease domain. Here, such a dual domain protein, i.e. the Sulfolobus islandicus Csx1 (SisCsx1) was characterized. The enzyme exhibited metal-independent single-strand specific ribonuclease activity. In fact, SisCsx1 showed a basal RNase activity in the absence of ligand; upon the binding of an RNA ligand carrying four continuous adenosines at the 3′-end (3′-tetra-rA), the activated SisCsx1 degraded RNA substrate with a much higher turnover rate. Amino acid substitution mutants of SisCsx1 were obtained, and characterization of these mutant proteins showed that the CARF domain of the enzyme is responsible for binding to 3′-tetra-rA and the ligand binding strongly activates RNA cleavage by the HEPN domain. Since RNA polyadenylation is an important step in RNA decay in prokaryotes, and poly(A) RNAs can activate CARF domain proteins, the poly(A) RNA may function as an important signal in the cellular responses to viral infection and environmental stimuli, leading to degradation of both viral and host transcripts and eventually to cell dormancy or cell death. |
| Databáze: | OpenAIRE |
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