6YUD

Structure of Csx3/Crn3 from Archaeoglobus fulgidus in complex with cyclic tetra-adenylate (cA4)

Summary for 6YUD

• Entry DOI: 10.2210/pdb6yud/pdb
• Related: 3WZG 3WZH 3WZI
• Related PRD ID: PRD_002431
• Descriptor: Uncharacterized protein AF_1864, Cyclic tetraadenosine monophosphate (cA4) (3 entities in total)
• Functional Keywords: ring nuclease, crispcyclo tetra-adenylate, rna binding protein
• Biological source: Archaeoglobus fulgidus; More
• Total number of polymer chains: 15
• Total formula weight: 130374.20

Authors

McQuarrie, S.,Gloster, T.M.,White, M.F.,Graham, S.,Athukoralage, J.S.,Gruschow, S. (deposition date: 2020-04-27, release date: 2020-08-19, Last modification date: 2024-01-24)

Primary citation

Athukoralage, J.S.,McQuarrie, S.,Gruschow, S.,Graham, S.,Gloster, T.M.,White, M.F.
Tetramerisation of the CRISPR ring nuclease Crn3/Csx3 facilitates cyclic oligoadenylate cleavage.
Elife, 9:-, 2020

PubMed Abstract: Type III CRISPR systems detect foreign RNA and activate the cyclase domain of the Cas10 subunit, generating cyclic oligoadenylate (cOA) molecules that act as a second messenger to signal infection, activating nucleases that degrade the nucleic acid of both invader and host. This can lead to dormancy or cell death; to avoid this, cells need a way to remove cOA from the cell once a viral infection has been defeated. Enzymes specialised for this task are known as ring nucleases, but are limited in their distribution. Here, we demonstrate that the widespread CRISPR associated protein Csx3, previously described as an RNA deadenylase, is a ring nuclease that rapidly degrades cyclic tetra-adenylate (cA). The enzyme has an unusual cooperative reaction mechanism involving an active site that spans the interface between two dimers, sandwiching the cA substrate. We propose the name Crn3 (CRISPR associated ring nuclease 3) for the Csx3 family.

PubMed: 32597755
DOI: 10.7554/eLife.57627

Experimental method

X-RAY DIFFRACTION (1.84 Å)