This is a Bacterial family of unknown function. Family members are predicted to belong to Type VII secretion (T7S) system. There is a conserved YxxxD/E sequence. It is a general secretion signal that is present in all known mycobacterial T7S substrates or substrate complexes [1].

1: General secretion signal for the mycobacterial type VII secretion pathway. Daleke MH, Ummels R, Bawono P, Heringa J, Vandenbroucke-Grauls CM, Luirink J, Bitter W; Proc Natl Acad Sci U S A. 2012;109:11342-11347. PMID:22733768