Ribosome Biogenesis: Role of Small Nucleolar RNA in Maturation of Eukaryotic rRNA

Much excitement has been generated recently by theelucidation of the structure of the ribosome by X-raycrystallography and cryo-electron microscopy, providinginsights on how this molecular machine works (see otherpapers in this volume). The ribosome appears to be a ribozyme with catalytic activity for protein synthesis in itsRNA moiety (Noller et al. 1992; Green and Noller 1997;Khaitovich et al. 1999; Muth et al. 2000; Nissen et al.2000). Evidence is beginning to mount that there are conformational changes in the ribosome during translation,reflecting dynamic alterations in the underlying ribosomal RNA (rRNA) structure (Lodmell and Dahlberg 1997;Gabashvili et al. 1999; Frank and Agrawal 2000; Pape etal. 2000; Stark et al. 2000; VanLoock et al. 2000; Ogle etal. 2001). The structure of the ribosome is key to its function, and therefore it is absolutely essential that rRNA befolded correctly from among the myriad possibilities.How does the cell accomplish this awesome task to formthe ribosome...