This domain of unknown function is found at the C-terminal end of proteins mainly from Legionella, including lpg0944 from Legionella pneumophila (Swiss:Q5ZWY9), which is thought to be an effector of the Icm/Dot translocation system from this bacteria. This domain folds into an all-alpha structure [1].

1: Diverse mechanisms of metaeffector activity in an intracellular bacterial pathogen, Legionella pneumophila. Urbanus ML, Quaile AT, Stogios PJ, Morar M, Rao C, Di Leo R, Evdokimova E, Lam M, Oatway C, Cuff ME, Osipiuk J, Michalska K, Nocek BP, Taipale M, Savchenko A, Ensminger AW; Mol Syst Biol. 2016;12:893. PMID:27986836