7VU8

L7-Tir domain with bound ligand

Summary for 7VU8

• Entry DOI: 10.2210/pdb7vu8/pdb
• EMDB information: 32126
• Descriptor: Flax rust resistance protein, 2',3'- cyclic AMP (2 entities in total)
• Functional Keywords: nucleic acid hydrolysis complex, hydrolase
• Biological source: Linum usitatissimum (Flax, Linum humile)
• Total number of polymer chains: 1
• Total formula weight: 23861.55

Authors

Tan, Y.,Xu, C.,Yu, D.,Song, W.,Wu, B.,Schulze-Lefert, P.,Chai, J. (deposition date: 2021-11-01, release date: 2022-06-01, Last modification date: 2024-06-26)

Primary citation

Yu, D.,Song, W.,Tan, E.Y.J.,Liu, L.,Cao, Y.,Jirschitzka, J.,Li, E.,Logemann, E.,Xu, C.,Huang, S.,Jia, A.,Chang, X.,Han, Z.,Wu, B.,Schulze-Lefert, P.,Chai, J.
TIR domains of plant immune receptors are 2',3'-cAMP/cGMP synthetases mediating cell death.
Cell, 185:2370-2386.e18, 2022

PubMed Abstract: 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.

PubMed: 35597242
DOI: 10.1016/j.cell.2022.04.032

Experimental method

ELECTRON MICROSCOPY (3 Å)