This entry represents the mammalian BAF250a/b and its homologue osa from fruit flies [1]. They are part of the SWI/SNF-like ATP-dependent chromatin remodelling complex that regulates gene expression through regulating nucleosome remodelling. In humans there are two BAF250 isoforms, BAF250a/ARID1a and BAF250b/ARID1b. BAF250a/b may be E3 ubiquitin ligases that target histone H2B [2].

1: Osa-containing Brahma chromatin remodeling complexes are required for the repression of wingless target genes. Collins RT, Treisman JE; Genes Dev. 2000;14:3140-3152. PMID:11124806

2: Mammalian SWI/SNF--a subunit BAF250/ARID1 is an E3 ubiquitin ligase that targets histone H2B. Li XS, Trojer P, Matsumura T, Treisman JE, Tanese N; Mol Cell Biol. 2010;30:1673-1688. PMID:20086098