Fig. 4: Structure of the human mitochondrial RNase Z in pre-cleavage complex with pre-tRNAHis(0,Ser).
From: Structural basis for human mitochondrial tRNA maturation
a Cryo-EM density map and cartoon representation of the structure of ELAC2 poised to process the TRMT10C/SDR5C1-bound pre-tRNAHis(0,Ser), with the color code indicated in Fig. 1a, b. b Superimposition of ELAC2 with ELAC1 homodimer (PDB 3ZWF). c Substrate-bound ELAC2 active site and metal-ion binding. Residues in the active site and the pre-tRNAHis(0,Ser) are shown in stick representation. Zn1 is shown as a solid marine sphere (with the density map in purple), and Zn2 was modeled on the basis of the ELAC1 crystal structure (PDB 3ZFW), and is shown as a light-purple sphere. d Vacuum electrostatics surface representation of ELAC2 in the complex with TRMT10C/SDR5C1-bound pre-tRNAHis(0,Ser). Positive charges are in blue, whereas negative ones are in red with the maximum color saturation corresponding to −5 kT/e (red) and +5 kT/e (blue). pre-tRNAHis(0,Ser) is represented as ribbon and sticks with the color code indicated in Fig. 1a. e Substrate-bound ELAC2 active site and pre-tRNAHis(0,Ser) binding, the insets shows the binding of C73 from tRNAHis and, G1 and A2 from tRNASer(AGY) at the interface between the ELAC2 β-lactamase domains with the density map for the tRNAs in orange. f Interactions between ELAC2 and, C73 from tRNAHis and G1 from tRNASer(AGY); Interactions between ELAC2 and G1 from tRNAHis; the density map is represented in orange for the tRNAs. g Density map showing the interactions between ELAC2 and TRMT10C at the level of the T-loop of tRNAHis; DSF assays testing the ability of ELAC2 and deletion mutant Δ(249-302) to bind pre-tRNAHis(0,Ser). Data were analysed by one-way ANOVA using a F test statistic. P-values are indicated as follows: ns for P = 0.61 and **** for P < 0.0001, n = 3 technical replicates; the error bars are SD. Cleavage assays of ELAC2 and deletion mutant Δ(249-302) on pre-tRNAHis(0,Ser) for 5 and 30 minutes, marker M2 is as in Fig. 1c. The gel is representative of three experiments. Source data are provided as a Source Data file.
