Download MendeleyAnalysis of a Critical Interaction within the Archaeal Box C/D Small Ribonucleoprotein Complex
Hardin, J.W., Reyes, F.E., Batey, R.T.(2009) J Biol Chem 284: 15317-15324
- PubMed: 19336398
- DOI: https://doi.org/10.1074/jbc.M901368200
- Primary Citation of Related Structures:
3GQU, 3GQX - PubMed Abstract:
In archaea and eukarya, box C/D ribonucleoprotein (RNP) complexes are responsible for 2'-O-methylation of tRNAs and rRNAs. The archaeal box C/D small RNP complex requires a small RNA component (sRNA) possessing Watson-Crick complementarity to the target RNA along with three proteins: L7Ae, Nop5p, and fibrillarin. Transfer of a methyl group from S-adenosylmethionine to the target RNA is performed by fibrillarin, which by itself has no affinity for the sRNA-target duplex. Instead, it is targeted to the site of methylation through association with Nop5p, which in turn binds to the L7Ae-sRNA complex. To understand how Nop5p serves as a bridge between the targeting and catalytic functions of the box C/D small RNP complex, we have employed alanine scanning to evaluate the interaction between the Pyrococcus horikoshii Nop5p domain and an L7Ae box C/D RNA complex. From these data, we were able to construct an isolated RNA-binding domain (Nop-RBD) that folds correctly as demonstrated by x-ray crystallography and binds to the L7Ae box C/D RNA complex with near wild type affinity. These data demonstrate that the Nop-RBD is an autonomously folding and functional module important for protein assembly in a number of complexes centered on the L7Ae-kinkturn RNP.
Organizational Affiliation:
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
