This family consists of a repeated sequence element found in the LMP group of surface-located membrane proteins of Mycoplasma hominis. The the number of repeats in the protein affects the tendency of cells to spontaneously aggregate. Agglutination may be an important factor in colonisation. Non-agglutinating microorganisms might easily be distributed whereas aggregation might provide a better chance to avoid an antibody response since some of the epitopes may be buried [1].

1: Selection of Mycoplasma hominis PG21 deletion mutants by cultivation in the presence of monoclonal antibody 552. Jensen LT, Ladefoged S, Birkelund S, Christiansen G; Infect Immun 1995;63:3336-3347. PMID:7543881