The N terminal domain of 'Tumour necrosis factor receptor type 1 associated death domain protein' (TRADD) folds into an alpha-beta sandwich with a four-stranded beta sheet and six alpha helices, each forming one layer of the structure. The domain allows docking of TRADD onto 'tumour necrosis factor receptor-associated factor' (TRAF): the binding is at the beta-sandwich domain, away from the coiled-coil domain. Binding ensures the recruitment of cIAPs to the signaling complex, which may be important for direct caspase-8 inhibition and the immediate suppression of apoptosis at the apical point of the cascade [1]. This domain is structurally related to the small-molecule-binding ACT domain (RRM-like fold) [2].

1: Solution structure of N-TRADD and characterization of the interaction of N-TRADD and C-TRAF2, a key step in the TNFR1 signaling pathway. Tsao DH, McDonagh T, Telliez JB, Hsu S, Malakian K, Xu GY, Lin LL; Mol Cell. 2000;5:1051-1057. PMID:10911999

2: Bacterial death and TRADD-N domains help define novel apoptosis and immunity mechanisms shared by prokaryotes and metazoans. Kaur G, Iyer LM, Burroughs AM, Aravind L; Elife. 2021; [Epub ahead of print] PMID:34061031