The Structure of the Rlmb 23S Rrna Methyltransferase Reveals a New Methyltransferase Fold with a Unique Knot
Michel, G., Sauve, V., Larocque, R., Li, Y., Matte, A., Cygler, M.(2002) Structure 10: 1303
- PubMed: 12377117 
- DOI: https://doi.org/10.1016/s0969-2126(02)00852-3
- Primary Citation of Related Structures:  
1GZ0 - PubMed Abstract: 
In Escherichia coli, RlmB catalyzes the methylation of guanosine 2251, a modification conserved in the peptidyltransferase domain of 23S rRNA. The crystal structure of this 2'O-methyltransferase has been determined at 2.5 A resolution. RlmB consists of an N-terminal domain connected by a flexible extended linker to a catalytic C-terminal domain and forms a dimer in solution. The C-terminal domain displays a divergent methyltransferase fold with a unique knotted region, and lacks the classic AdoMet binding site features. The N-terminal domain is similar to ribosomal proteins L7 and L30, suggesting a role in 23S rRNA recognition. The conserved residues in this novel family of 2'O-methyltransferases cluster in the knotted region, suggesting the location of the catalytic and AdoMet binding sites.
Organizational Affiliation: 
Biotechnology Research Institute, National Research Council of Canada and Montreal Joint Centre for Structural Biology, Montreal, Quebec, Canada.