Schematic diagram showing structure of TLR and NLR family. TLR: toll-like receptor; NLRP: NOD-like receptor containing pyrin domain; NLRC: NOD-like receptor containing NLR-containing caspase activation and recruitment domain; NLRB: NOD-like receptor containing baculovirus inhibitor of apoptosis protein repeat domain; LRR: leucine-rich repeat; TIR: toll/il-1 receptor; PYD: pyrin domain; CARD: caspase activation and recruitment domain; BIR: baculovirus inhibitor of apoptosis protein repeat. The figure shows the structure of a TLR containing a TIR domain present inside nucleus which is involved in signalling pathway and an LRR domain present in the cytoplasm which is involved in pathogen recognition. NLR are intracellular receptors containing a C-terminal LRR domain, a central NACHT domain, and a variable N-terminal domain which can be a PYD, a CARD, or a BIR domain.
