Structure of Y. lipolytica Trm9-Trm112 complex, a methyltransferase modifying U34 in the anticodon loop of some tRNAs
Classification:
TRANSFERASE
Technique:
X-Ray Diffraction
Resolution:
2.5
R value free:
0.242
R value observed:
0.201
R value work:
0.199
Abstract of the PDB Structure's related Publication:
Most of the factors involved in translation (tRNA, rRNA and proteins) are subject to post-transcriptional and post-translational modifications, which participate in the fine-tuning and tight control of ribosome and protein synthesis processes. In eukaryotes, Trm112 acts as an obligate activating platform for at least four methyltransferases (MTase) involved in the modification of 18S rRNA (Bud23), tRNA (Trm9 and Trm11) and translation termination factor eRF1 (Mtq2). Trm112 is then at a nexus between ribosome synthesis and function. Here, we present a structure-function analysis of the Trm9-Trm112 complex, which is involved in the 5-methoxycarbonylmethyluridine (mcm(5)U) modification of the tRNA anticodon wobble position and hence promotes translational fidelity. We also compare the known crystal structures of various Trm112-MTase complexes, highlighting the structural plasticity allowing Trm112 to interact through a very similar mode with its MTase partners, although those share less than 20% sequence identity.
tRNA methyltransferase in S.cerevisiae. It catalyzes the sterification of modified uridine nucleotides resulting in the formation of 5-methylcarbonylmethyluridine in tRNAArg-3 and 5-methylcarbonylmethyl-2-thiouridine in tRNAGlu. In yeast cells, disruption of TRM9 gene results in the complete loss of these modified wobble bases and increased sensitivity at 37 °C to paramomycin, a translational inhibitor (Khalor & Clarke 2003)