Immobilized eukaryotic 5.8 S RNA binds Escherichia coli and rat liver ribosomal proteins.

The eukaryotic ribosome contains two lowmolecular weight RNAs, 5 S RNA and 5.8 S RNA (for reviews [ 1,2]). The larger species is specific only for eukaryotic ribosome and, like 5 S RNA, is a component of the large subunit. Earlier we found that the immobilized rat liver 5.8 S RNA forms a complex with 60 S subunit proteins L.5, L6, L7 and L18 [3]. The yeast 5.8 S RNA has been shown to interact also with E. coli ribosomal proteins L18 and L25 141, specific for the prokaryotic 5 S RNA. Here we demonstrate that the immobilized rat liver and bovine 5.8 S RNAs bind rat liver 40 S ribosomal subunit proteins S6, S14 and S23/S24.5.8 S RNAs bind also a set of E. coli 50 S subunit proteins consisting of L2, L17, L19 for the yeast 5.8 S RNA and L2, L17, L19, L20 and L21 for bovine liver 5.8 S RNA. L18 was visible as a minor protein of the yeast 5.8 S RNA-protein complex.