DD (Oligomeric Death Domain Complex)

Death domains proteins are part of the programmed cell death pathway. They form a complex by oligomerization that is mediated by multiple units of the death domain. This domain is a bundle of about six helices.

The 7 red proteins are CRADD and the 5 blue proteins are a similar DD protein. Different, but similar domains are highlighted in yellow.

Death domain assembly mechanism revealed by crystal structure of the oligomeric PIDDosome core complex.
Park HH, Logette E, Raunser S, Cuenin S, Walz T, Tschopp J, Wu H.
Cell. 2007 Feb 9;128(3):533-46.

(PubMed)

2of5 (PDB)

Helical assembly in the death domain (DD) superfamily.
Ferrao R, Wu H.
Curr Opin Struct Biol. 2012 Apr;22(2):241-7. doi: 10.1016/j.sbi.2012.02.006. Epub 2012 Mar 17. Review.
PMID: 22429337 Free PMC Article

Abstract
Death domain (DD) superfamily members play a central role in apoptotic and inflammatory signaling through formation of oligomeric molecular scaffolds. These scaffolds promote the activation of proinflammatory and apoptotic initiator caspases, as well as Ser/Thr kinases. Interactions between DDs are facilitated by a conserved set of interaction surfaces, type I, type II, and type III. Recently structural information on a ternary complex containing the DDs of MyD88, IRAK4, and IRAK2 and a binary complex containing Fas and FADD DDs has become available. This review will focus on how the three DD interaction surfaces cooperate to facilitate the assembly of these oligomeric signaling complexes.

The death domain superfamily in intracellular signaling of apoptosis and inflammation.
Park HH, Lo YC, Lin SC, Wang L, Yang JK, Wu H.
Annu Rev Immunol. 2007;25:561-86. Review.
PMID: 17201679 Free PMC Article

Abstract
The death domain (DD) superfamily comprising the death domain (DD) subfamily, the death effector domain (DED) subfamily, the caspase recruitment domain (CARD) subfamily, and the pyrin domain (PYD) subfamily is one of the largest domain superfamilies. By mediating homotypic interactions within each domain subfamily, these proteins play important roles in the assembly and activation of apoptotic and inflammatory complexes. In this chapter, we review the molecular complexes assembled by these proteins, the structural and biochemical features of these domains, and the molecular interactions mediated by them. By analyzing the potential molecular basis for the function of these domains, we hope to provide a comprehensive understanding of the function, structure, interaction, and evolution of this important family of domains.