A conserved alpha helical domain with a characteristic LXXLL motif [1] [2]. The LXXLL motif is detected in diverse transcription factors, coactivators and corepressors and is implicated in mediating interactions between them [3]. The ASXH domain is found in animals, fungi and plants [4] and is predicted to play a role in mediating contact between transcription factors and chromatin-associated complexes. In Drosophila Asx and Human ASXL1, the ASXH domain is predicted to mediate interactions with the Calypso and BAP1 deubiquitinases (DUBs) which further belong to the UCHL5/UCH37 clade of DUBs [4].

1: Functional conservation of Asxl2, a murine homolog for the Drosophila enhancer of trithorax and polycomb group gene Asx. Baskind HA, Na L, Ma Q, Patel MP, Geenen DL, Wang QT; PLoS One. 2009;4:e4750. PMID:19270745

2: Additional sex combs-like 1 belongs to the enhancer of trithorax and polycomb group and genetically interacts with Cbx2 in mice. Fisher CL, Lee I, Bloyer S, Bozza S, Chevalier J, Dahl A, Bodner C, Helgason CD, Hess JL, Humphries RK, Brock HW; Dev Biol. 2010;337:9-15. PMID:19833123

3: The LxxLL motif: a multifunctional binding sequence in transcriptional regulation. Plevin MJ, Mills MM, Ikura M; Trends Biochem Sci. 2005;30:66-69. PMID:15691650

4: The HARE-HTH and associated domains: novel modules in the coordination of epigenetic DNA and protein modifications. Aravind L, Iyer LM; Cell Cycle. 2012;11:119-131. PMID:22186017