An siRNA ribonucleoprotein is found associated with polyribosomes in Trypanosoma brucei

(A) The salt-extracted material from the ribosome pellet was loaded on a Superdex-200 column, and selected fractions were Northern-blotted with a MT40 sense riboprobe. (B) An equivalent amount of the salt-extracted fraction that was analyzed in A was digested with proteinase-K and phenol-extracted prior to chromatography on Superdex-200. The elution positions of carbonic anhydrase (30 kD), bovine serum albumin (66 kD), and thyroglobulin (669 kD) are indicated.