C-terminal jelly roll/Ig-like domain (C-JID) was defined in cryogenic electron microscopy (cryoEM) structures of plant intracellular immune receptors containing Toll/interleukin-1 receptor (TIR, PF01582), nucleotide-binding (NB-ARC, PF00931) and leuc ...
C-terminal jelly roll/Ig-like domain (C-JID) was defined in cryogenic electron microscopy (cryoEM) structures of plant intracellular immune receptors containing Toll/interleukin-1 receptor (TIR, PF01582), nucleotide-binding (NB-ARC, PF00931) and leucine-rich repeat (LRR) domains (TIR-NLRs) [1,2]. Structurally, the C-JID core is represented by a beta-sandwich made up of 8 to 9 beta-strands. C-JID matches the so-called post-LRR or C-terminal non-LRR domain detected earlier via MEME and BLAST searches [3,7]. The domain showed a strong distribution bias towards TIR-NLRs of dicotyledonous plant species despite broader taxonomic distribution of TIR-NLR in plant groups [1-7]. Structure-function analyses of cryoEM structures suggest that C-JID domains play a role in substrate recognition, such as binding to effector proteins from pathogens, and thus are involved in the initiation of signaling by TIR-NLR receptors [1,2]. Presence of C-JID (or post-LRR) and its importance for the function of Arabidopsis TIR-NLR RPS4 that partners with RRS1 for effector recognition suggest that C-JID has additional functions [4-6].