Crystal structure of Sulfolobus solfataricus Nop5 (1-262) and fibrillarin complex
Classification:
TRANSFERASE
Technique:
X-Ray Diffraction
Resolution:
2.6
R value free:
0.285
R value observed:
0.235
R value work:
0.232
Abstract of the PDB Structure's related Publication:
Box C/D guide RNAs are abundant noncoding RNAs that primarily function to direct the 2'-O-methylation of specific nucleotides by base-pairing with substrate RNAs. In archaea, a bipartite C/D RNA assembles with L7Ae, Nop5, and the methyltransferase fibrillarin into a modification enzyme with unique substrate specificity. Here, we determined the crystal structure of an archaeal C/D RNA-protein complex (RNP) composed of all 3 core proteins and an engineered half-guide RNA at 4 A resolution, as well as 2 protein substructures at higher resolution. The RNP structure reveals that the C-terminal domains of Nop5 in the dimeric complex provide symmetric anchoring sites for 2 L7Ae-associated kink-turn motifs of the C/D RNA. A prominent protrusion in Nop5 seems to be important for guide RNA organization and function and for discriminating the structurally related U4 snRNA. Multiple conformations of the N-terminal domain of Nop5 and its associated fibrillarin in different structures indicate the inherent flexibility of the catalytic module, suggesting that a swinging motion of the catalytic module is part of the enzyme mechanism. We also built a model of a native C/D RNP with substrate and fibrillarin in an active conformation. Our results provide insight into the overall organization and mechanism of action of C/D RNA-guided RNA methyltransferases.
Forms a stable heterodimer with METTL14. The complex catalyses the AdoMet dependent N6-methylation of internal adenosine in mammalian mRNA. METTL3 displays a regulatory role on several cellular functions. METTL3 is critical for viability of mammalian cells. Notice, the methyl group of m6A in mRNA can be removed by the obesity-associated protein FTO (demethylase enzyme.)
Structure prediction and phylogenetic analysis of a functionally diverse family of proteins homologous to the MT-A70 subunit of the human mRNA:m(6)A methyltransferase.
N6-adenosine methylation in mRNA: substrate specificity and enzyme complexity.
Purification and cDNA cloning of the AdoMet-binding subunit of the human mRNA (N6-adenosine)-methyltransferase.
Structure prediction and phylogenetic analysis of a functionally diverse family of proteins homologous to the MT-A70 subunit of the human mRNA:m(6)A methyltransferase.