This is the C-terminal scaffold dimerization domain (SDD) found in inhibitor of nuclear factor kappa-B kinase subunit beta IKBKB (EC:2.7.11.10) [1]. IKK2 also known as IKBKB is one of the core component of IKB kinases (IKK). IKB kinase (IKK) is an enzyme that quickly becomes active in response to diverse stresses on a cell. The SDD consists primarily of two long alpha-helices [2].

1: Crystal structure of a human IkappaB kinase beta asymmetric dimer. Liu S, Misquitta YR, Olland A, Johnson MA, Kelleher KS, Kriz R, Lin LL, Stahl M, Mosyak L; J Biol Chem. 2013;288:22758-22767. PMID:23792959

2: A structural basis for IkappaB kinase 2 activation via oligomerization-dependent\ttrans auto-phosphorylation. Polley S, Huang DB, Hauenstein AV, Fusco AJ, Zhong X, Vu D, Schrofelbauer B, Kim Y, Hoffmann A, Verma IM, Ghosh G, Huxford T; PLoS Biol. 2013;11:e1001581. PMID:23776406