TcP2β ribosomal protein genes in Trypanosoma cruzi are encoded by four different loci, H6.4, H1.8, H1.5 and H1.3. All loci have a similar organization, except for H1.8 that harbors two TcP2β genes arranged in tandem and separated by a short repetitive sequence, named SIRE (short interspersed repetitive element), which is also found upstream of the first gene of the tandem and downstream of the second.