FIG. 4.

The NRS RG11 mutation disrupts both U11 and U1 snRNP binding. The indicated biotinylated (+) or nonbiotinylated (−) RNA (990 fmol) was incubated in nuclear extract and affinity selected with streptavidin-agarose beads (see Materials and Methods), and the snRNA components of bound snRNPs were extracted and identified by Northern analysis with U1 and U11 antisense riboprobes. The band of slightly slower migration than the U11 band in lane 4 is the Ad3′ substrate. U1 and U11 snRNA markers (M) were extracted from nuclear extract. The positions of U1 and U11 snRNA are indicated at the left. RNAs are designated as in Fig. 1.