Figure 1.

Immunoprecipitation of TMG-capped Euglena small RNAs. Samples were 3′-end-labeled with [5′-³²P]pCp and RNA ligase and were resolved in a 10% polyacrylamide/7 M urea sequencing gel. (A) Total RNA. The most abundant labeled bands in this sample [1 (163 nt), 3 (350 nt), 7 (235 nt), and 10 (164 nt)] correspond to components of the fragmented large subunit rRNA (33). Band X (181 nt) was generated by ligation of large subunit rRNA species 12 to the 3′-end of large subunit rRNA species 14 (33). (B) Anti-TMG immunoprecipitate. Chemical sequencing revealed that the mAb enriched for U1 (see Results and Discussion), U2, and U4 (identified by sequence analysis and comparison with homologous sequences; M.N.S., unpublished results) snRNAs as well as four bands (A–D) containing variant forms of U3 small nucleolar RNA (34).