The structure of this family has been solved. It comprises a 12-stranded beta barrel with a central C-terminal alpha helix. This helix is thought to be a transmembrane helix. It is structurally similar to the C-terminal domain of the Tubby protein [1]. In plants it plays a role in defense against pathogens [2].

1: Phospholipid scramblases and Tubby-like proteins belong to a new superfamily of membrane tethered transcription factors. Bateman A, Finn RD, Sims PJ, Wiedmer T, Biegert A, Soding J; Bioinformatics. 2009;25:159-162. PMID:19010806

2: The oomycete response gene LURP1 is required for defense against Hyaloperonospora parasitica in Arabidopsis thaliana. Knoth C, Eulgem T; Plant J. 2008;55:53-64. PMID:18346188