This domain forms an alpha-helical homodimer in ELF4 proteins. Protein EARLY FLOWERING 4 (Elf4) is a component of the central CCA1/LHY-TOC1 feedback loop in the circadian clock that promotes clock accuracy and is required for sustained rhythms in the absence of daily light/dark cycles [1, 2].

1: The ELF4 gene controls circadian rhythms and flowering time in Arabidopsis thaliana. Doyle MR, Davis SJ, Bastow RM, McWatters HG, Kozma-Bognar L, Nagy F, Millar AJ, Amasino RM; Nature. 2002;419:74-77. PMID:12214234

2: Integrating ELF4 into the circadian system through combined structural and functional studies. Kolmos E, Nowak M, Werner M, Fischer K, Schwarz G, Mathews S, Schoof H, Nagy F, Bujnicki JM, Davis SJ; HFSP J. 2009;3:350-366. PMID:20357892