This domain appears to be found only in a small family of Chlamydia species [1]. It is usually found repeated. This domain can be found in translocated actin-recruiting phosphoprotein (Tarp) from Chlamydia trachomatis serovar L2. Tarp appears to initiate or participate in signalling events that regulate the actin recruitment, which ultimately leads to internalisation [2].

1: The Chlamydia psittaci genome: a comparative analysis of intracellular pathogens. Voigt A, Schofl G, Saluz HP; PLoS One. 2012;7:e35097. PMID:22506068

2: A chlamydial type III translocated protein is tyrosine-phosphorylated at the site of entry and associated with recruitment of actin. Clifton DR, Fields KA, Grieshaber SS, Dooley CA, Fischer ER, Mead DJ, Carabeo RA, Hackstadt T; Proc Natl Acad Sci U S A. 2004;101:10166-10171. PMID:15199184