7X5K image
Entry Detail
PDB ID:
7X5K
EMDB ID:
Keywords:
Title:
Tir-dsDNA complex, the initial binding state
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2022-03-04
Release Date:
2022-06-08
Method Details:
Experimental Method:
Resolution:
3.80 Å
Aggregation State:
FILAMENT
Reconstruction Method:
HELICAL
Macromolecular Entities
Polymer Type:polydeoxyribonucleotide
Description:DNA (43-MER)
Chain IDs:A (auth: B), C (auth: Q)
Chain Length:43
Number of Molecules:2
Biological Source:DNA molecule
Polymer Type:polypeptide(L)
Description:Flax rust resistance protein
Mutations:E197G
Chain IDs:E (auth: C), F (auth: A), G (auth: I), H (auth: D), I (auth: M), J (auth: F), K (auth: J), L (auth: P), M (auth: N), N (auth: G), O (auth: K), P (auth: R), Q (auth: O), R (auth: H), S (auth: L), T
Chain Length:204
Number of Molecules:16
Biological Source:Linum usitatissimum
Polymer Type:polydeoxyribonucleotide
Description:DNA (43-MER)
Chain IDs:B (auth: E), D (auth: S)
Chain Length:43
Number of Molecules:2
Biological Source:DNA molecule
Ligand Molecules
Primary Citation
TIR domains of plant immune receptors are 2',3'-cAMP/cGMP synthetases mediating cell death.
Cell 185 2370 2386.e18 (2022)
PMID: 35597242 DOI: 10.1016/j.cell.2022.04.032

Abstact

2',3'-cAMP is a positional isomer of the well-established second messenger 3',5'-cAMP, but little is known about the biology of this noncanonical cyclic nucleotide monophosphate (cNMP). Toll/interleukin-1 receptor (TIR) domains of nucleotide-binding leucine-rich repeat (NLR) immune receptors have the NADase function necessary but insufficient to activate plant immune responses. Here, we show that plant TIR proteins, besides being NADases, act as 2',3'-cAMP/cGMP synthetases by hydrolyzing RNA/DNA. Structural data show that a TIR domain adopts distinct oligomers with mutually exclusive NADase and synthetase activity. Mutations specifically disrupting the synthetase activity abrogate TIR-mediated cell death in Nicotiana benthamiana (Nb), supporting an important role for these cNMPs in TIR signaling. Furthermore, the Arabidopsis negative regulator of TIR-NLR signaling, NUDT7, displays 2',3'-cAMP/cGMP but not 3',5'-cAMP/cGMP phosphodiesterase activity and suppresses cell death activity of TIRs in Nb. Our study identifies a family of 2',3'-cAMP/cGMP synthetases and establishes a critical role for them in plant immune responses.

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Primary Citation of related structures