A yeast three-hybrid system was employed to analyze interactions
in vivo between H1 RNA, the RNA subunit of human nuclear
RNase P, and eight of the protein subunits of the enzyme.
The genetic analysis indicates that subunits Rpp21, Rpp29,
Rpp30, and Rpp38 interact directly with H1 RNA. The results
of direct UV crosslinking studies of the purified RNase
P holoenzyme confirm the results of the three-hybrid assay.