This domain of unknown function is found in eukaryotes on neurobeachin and BEACH domain-containing proteins (BDCPs) [1,2]. Mutations in this proteins are associated with Lipopolysaccharide-responsive and beige-like anchor (LRBA) deficiency [2]. According to structure prediction is adopts an alpha-helical solenoid structure.

1: SEL-2, the C. elegans neurobeachin/LRBA homolog, is a negative regulator of lin-12/Notch activity and affects endosomal traffic in polarized epithelial cells. de Souza N, Vallier LG, Fares H, Greenwald I; Development. 2007;134:691-702. PMID:17215302

2: Novel compound heterozygous stop-gain mutations of LRBA in a Vietnamese patient with Common Variable Immune Deficiency. Phan ANL, Pham TTT, Huynh N, Nguyen TM, Cao CTT, Nguyen DT, Le DT, Bui CB; Mol Genet Genomic Med. 2020;8:e1216. PMID:32154999