RNA-guided RNA modification: functional organization of the archaeal H/ACA RNP

Genes Dev. 2005 May 15;19(10):1238-48. doi: 10.1101/gad.1309605. Epub 2005 May 3.


In eukaryotes and archaea, uridines in various RNAs are converted to pseudouridines by RNA-guided RNA modification complexes termed H/ACA RNPs. Guide RNAs within the complexes base-pair with target RNAs to direct modification of specific ribonucleotides. Cbf5, a protein component of the complex, likely catalyzes the modification. However, little is known about the organization of H/ACA RNPs and the roles of the multiple proteins thought to comprise the complexes. We have reconstituted functional archaeal H/ACA RNPs from recombinant components, defined the components necessary and sufficient for function, and determined the direct RNA-protein and protein-protein interactions that occur between the components. The results provide substantial insight into the functional organization of this RNP. The functional complex requires a guide RNA and each of four proteins: Cbf5, Gar1, L7Ae, and Nop10. Two proteins interact directly with the guide RNA: L7Ae and Cbf5. L7Ae does not interact with other H/ACA RNP proteins in the absence of the RNA. We have defined two novel functions for Cbf5. Cbf5 is the protein that specifically recognizes and binds H/ACA guide RNAs. In addition, Cbf5 recruits the two other essential proteins, Gar1 and Nop10, to the pseudouridylation guide complex.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Archaeal Proteins / metabolism*
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism*
  • Nucleic Acid Conformation
  • Protein Binding / genetics
  • Protein Binding / physiology
  • Pseudouridine / genetics
  • Pseudouridine / metabolism
  • Pyrococcus furiosus / genetics
  • Pyrococcus furiosus / physiology*
  • RNA Processing, Post-Transcriptional / genetics
  • RNA Processing, Post-Transcriptional / physiology*
  • RNA, Archaeal / metabolism*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Uridine / genetics
  • Uridine / metabolism


  • Archaeal Proteins
  • Multiprotein Complexes
  • RNA, Archaeal
  • RNA-Binding Proteins
  • Recombinant Proteins
  • Pseudouridine
  • Uridine