This domain family is found in bacteria, and is approximately 50 amino acids in length. There are two completely conserved residues (Y and W) that may be functionally important. This family consists of leucine-rich repeat proteins involved in type III secretion.

1: Salmonella typhimurium leucine-rich repeat proteins are targeted to the SPI1 and SPI2 type III secretion systems. Miao EA, Scherer CA, Tsolis RM, Kingsley RA, Adams LG, Baumler AJ, Miller SI; Mol Microbiol. 1999;34:850-864. PMID:10564523