Fig. 6: TRMT10C interactions with pre-tRNA for purine-9 N1-methylation.
From: Structural basis for human mitochondrial tRNA maturation
a Overview of the TRMT10C/pre-tRNAHis-Ser structure (Complex 2), SDR5C1 and PRORP have been removed for clarity. TRMT10C is represented as cartoon with the color code indicated in Fig. 1 and the pre-tRNAHis-Ser as red ribbon and sticks. The inset shows a close-up of the anticodon loop and TRMT10C structure in the cryo-EM density map. b Conformation of the SAM/SAH-binding loop in the TRMT10C MTase domain upon binding of SAH and tRNA (complex 2, in green) compared to the conformation in the structure with tRNA and without SAM/SAH (PDB 7ONU, in beige)25; Conformation of the RNA-binding loop in the TRMT10C MTase domain upon binding of tRNA (complex 2, in green) compared to the conformation in the structure of TRMT10C with no tRNA, but with SAM (PDB 5NFJ, in grey). c Interactions between tRNAHis (in red) and the helix (126-166, in green) of TRMT10C, the inset shows the interaction of nucleotide A46 with Y135 from TRMT10C NTD and K218 from TRMT10C MTase domain. d Methyltransferase assays with TRMT10C with different N-terminal deletions, Blk: assay without pre-tRNA. Data were analysed by one-way ANOVA using a Dunnett’s multiple comparison test. P-values are indicated as follows: ns for P = 0.15, *** for P = 0.0004 and **** for P < 0.0001, n = 3 technical replicates. The error bars are SD. Source data are provided as a Source Data file. e Interactions between A9 of pre-tRNAHis-Ser and G9 of pre-tRNAIle with conserved residues in the active site of TRMT10C. Potential hydrogen bonds are shown as dashed black lines.
