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Title | Structure of tRNA methyltransferase complex of Trm7 and Trm734 reveals a novel binding interface for tRNA recognition. |
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Journal, issue, pages | Nucleic Acids Res, Vol. 47, Issue 20, Page 10942-10955, Year 2019 |
Publish date | Nov 18, 2019 |
Authors | Akira Hirata / Keisuke Okada / Kazuaki Yoshii / Hiroyuki Shiraishi / Shinya Saijo / Kento Yonezawa / Nobutaka Shimizu / Hiroyuki Hori / |
PubMed Abstract | The complex between Trm7 and Trm734 (Trm7-Trm734) from Saccharomyces cerevisiae catalyzes 2'-O-methylation at position 34 in tRNA. We report biochemical and structural studies of the Trm7-Trm734 ...The complex between Trm7 and Trm734 (Trm7-Trm734) from Saccharomyces cerevisiae catalyzes 2'-O-methylation at position 34 in tRNA. We report biochemical and structural studies of the Trm7-Trm734 complex. Purified recombinant Trm7-Trm734 preferentially methylates tRNAPhe transcript variants possessing two of three factors (Cm32, m1G37 and pyrimidine34). Therefore, tRNAPhe, tRNATrp and tRNALeu are specifically methylated by Trm7-Trm734. We have solved the crystal structures of the apo and S-adenosyl-L-methionine bound forms of Trm7-Trm734. Small angle X-ray scattering reveals that Trm7-Trm734 exists as a hetero-dimer in solution. Trm7 possesses a Rossmann-fold catalytic domain, while Trm734 consists of three WD40 β-propeller domains (termed BPA, BPB and BPC). BPA and BPC form a unique V-shaped cleft, which docks to Trm7. The C-terminal region of Trm7 is required for binding to Trm734. The D-arm of substrate tRNA is required for methylation by Trm7-Trm734. If the D-arm in tRNAPhe is docked onto the positively charged area of BPB in Trm734, the anticodon-loop is located near the catalytic pocket of Trm7. This model suggests that Trm734 is required for correct positioning of tRNA for methylation. Additionally, a point-mutation in Trm7, which is observed in FTSJ1 (human Trm7 ortholog) of nosyndromic X-linked intellectual disability patients, decreases the methylation activity. |
External links | Nucleic Acids Res / PubMed:31586407 / PubMed Central |
Methods | SAS (X-ray synchrotron) / X-ray diffraction |
Resolution | 2.32 - 2.699 Å |
Structure data | SASDDR3: PDB-6jp6: PDB-6jpl: |
Chemicals | ChemComp-SO4: ChemComp-EPE: ChemComp-HOH: ChemComp-SAM: |
Source |
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Keywords | TRANSFERASE / tRNA methyltransferase / tRNA maturation |