5A7Z: Crystal Structure Of Sulfolobus Acidocaldarius Trm10 At 2.1 Angstrom Resolution

Purine nucleosides on position 9 of eukaryal and archaeal tRNAs are frequently modified in vivo by the post-transcriptional addition of a methyl group on their N1 atom. The methyltransferase Trm10 is responsible for this modification in both these domains of life. While certain Trm10 orthologues specifically methylate either guanosine or adenosine at position 9 of tRNA, others have a dual specificity. Until now structural information about this enzyme family was only available for the catalytic SPOUT domain of Trm10 proteins that show specificity toward guanosine. Here, we present the first crystal structure of a full length Trm10 orthologue specific for adenosine, revealing next to the catalytic SPOUT domain also N- and C-terminal domains. This structure hence provides crucial insights in the tRNA binding mechanism of this unique monomeric family of SPOUT methyltransferases. Moreover, structural comparison of this adenosine-specific Trm10 orthologue with guanosine-specific Trm10 orthologues suggests that the N1 methylation of adenosine relies on additional catalytic residues.
PDB ID: 5A7ZDownload
MMDB ID: 135398
PDB Deposition Date: 2015/7/10
Updated in MMDB: 2017/09
Experimental Method:
x-ray diffraction
Resolution: 2.1  Å
Source Organism:
Similar Structures:
Biological Unit for 5A7Z: monomeric; determined by author and by software (PISA)
Molecular Components in 5A7Z
Label Count Molecule
Protein (1 molecule)
tRNA (Adenine(9)-n1)-methyltransferase(Gene symbol: SACI_RS08005)
Molecule annotation
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