Small-size ribosomal RNA species in Trypanosoma cruzi.

Trypanosoma cruzi ribosomal RNA was analyzed electrophoresis. On agarose gels, where both large- and small-size species are grossly fractionable, it revealed two bands in the small-size region. These were similar in size to the mammalian 5.8 S and 5 S species. Increased resolution, however, showed these two bands to be composite. The pseudo 5.8 S band contained three, and the pseudo 5 S two, discretely sized molecules. The ribosomal binding of four of these five novel species is apparently dependent on large ribosomal subunit proteins. One species is hydrogen bonded to the beta species of 24 S ribosomal RNA. The five species were estimated to be 261, 217, 197, 141 and 110 nucleotides long.