Table 2.

Structural analysis of IKK subunits and their relatives

Protein	Origin	Details	Resolution	Structural features	References
IKKβ (aa 4–675)	Xenopus laevis	Complex with inhibitors Cmpd1 or Cmpd2	3.6 Å	KD + ULD + SDD; dimer (‘a pair of shears’)	29
IKKβ (aa 11–669)	Human	Constitutively active mutant (S177E/S181E)	4 Å	See above; open conformation; permits higher order oligomerization	28
His-IKKβ (aa 1-664; HIS tagged)	Human	Partially phosphorylated; bound to the staurosporine analog K252a	2.8 Å	See above; comparison of active and inactive kinase domains	27
NEMO (aa 44-111)	Human	Hybrid complex containing NEMO 44–111 and IKKα/β or IKKβ peptides	2.25/2.2 Å	Elongated and atypical parallel four-helix bundle	37
NEMO (aa 150-272)	Human	Hybrid complex containing NEMO 150-272 and vFLIP 1–178	3.2 Å	Coiled-coil dimer	38
NEMO (aa 251-337 His-tagged)	Mouse	Hybrid complex containing NEMO 251-337 and DARPin 1D5	2.95 Å	Coiled-coil dimer	40
NEMO (aa 254–337)	Human	NEMO 254-337 alone and in complex with di-ubiquitin	2.8/2.7 Å	Coiled-coil dimer	41
NEMO (ZF-WT and ZF-C417F)	Human	Solution structures determined by NMR	–	WT and mutant ZFs adopt a global ββα structure and bind zinc with comparable affinities; mutation causes instability	49
TBK1 (1–657; ΔCTD)	Human	A: Complex with inhibitors MRT67303 and BX795 B: D135N mutant (kinase dead)	2.4/2.5 Å and 3.3 Å	KD + ULD + SDD; Dimer; extensive interactions between different domains	32
TBK1 (1–657; ΔCTD)	Human	Complex of S172A mutant (inactive) or phosphorylated D135N mutant (active) with MRT67307/215 and BX795	2.6/4.0 Å	See above; Activation rearranges KD into an active conformation and maintains overall structure	31