beta-trefoil domain found in interleukin-36 receptor antagonist protein (IL-36RA) and similar proteins
IL-36RA, also called FIL1 delta, or IL-1-related protein 3, or IL-1RP3, or interleukin-1 HY1, or IL-1HY1, or interleukin-1 delta, or IL-1 delta, or interleukin-1 family member 5, or IL-1F5, or interleukin-1 receptor antagonist homolog 1, or IL-1ra homolog 1, or interleukin-1-like protein 1, or IL-1L1, inhibits the activity of interleukin-36 (IL36 alpha,IL36 beta and IL36 gamma) by binding to receptor IL1RL2 and preventing its association with the coreceptor IL1RAP for signaling. It is part of the IL-36 signaling system that is thought to be present in epithelial barriers and to take part in local inflammatory response; like the IL-1 system with which it shares the coreceptor. It may play a role in skin inflammation, as well as in the innate immune response to fungal pathogens, such as Aspergillus fumigatus. It may activate an anti-inflammatory signaling pathway by recruiting SIGIRR. IL-36RA contains a beta-trefoil domain, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.
Jiyao W et al.(2023). "The conserved domain database in 2023.",