Ribosome biogenesis is a crucial yet poorly understood and complex process in all cells. To date, most studies on eukaryotic ribosome biogenesis have relied on yeast genetics and whole cell analysis of ribosomal RNA processing. An early and critical step in ribosome biogenesis is the post-transcriptional modification of rRNA. Pseudouridylation is the most frequently occurring modification. Pseudouridylation is catalyzed by H/ACA small nucleolar ribonucleoproteins (snoRNPs) which are one of the two major classes of snoRNPs found within eukaryotes and archaea. H/ACA snoRNPs consist of four conserved core proteins Cbf5, Gar1, Nop10, and Nhp2 (eukaryotes), and a substrate specific H/ACA snoRNA. Mutations causing the rare inherited disease Dyskeratosis congenita are found in CBF5, NOP10, and NHP2. Here I report the purification of H/ACA protein Cbf5 in the presence of detergents. Additionally, I report initial in vitro RNA binding studies using Nhp2 and the snoRNA snR34 as well as the effects of Dyskeratosis congenita substitutions within Nhp2 on this interaction. / vii, 83 leaves : ill. ; 29 cm