Nop58 interacts with Nop17 through its C-terminal portion. (A) Schematics summarizing the results of two-hybrid assay with deletion mutants of Nop58 and Nop17. Nop58(324–512) mutant interacts with Nop17. (B) Co-immunoprecipitation of RNA with ProtA-Nop58 in the absence or presence of different amounts of Nop17. Incubation of total extract with IgG-sepharose beads was performed for 2 h at 4°C in the presence or absence of purified GST-Nop17. Co-immunoprecipitated U3 snoRNA was detected by northern blot. 5S rRNA was used as an internal control. (C) Quantitation of the U3 bands corrected by 5S bands after northern hybridization.