4JAK
Crystal structure of tRNA (Um34/Cm34) methyltransferase TrmL from Escherichia coli
Summary for 4JAK
| Entry DOI | 10.2210/pdb4jak/pdb |
| Related | 4JAL |
| Descriptor | tRNA (cytidine(34)-2'-O)-methyltransferase (2 entities in total) |
| Functional Keywords | spout, trna modification, methyltransferase, deep trefoil knot, sam binding, methylation, transferase |
| Biological source | Escherichia coli |
| Cellular location | Cytoplasm (Potential): P0AGJ7 |
| Total number of polymer chains | 2 |
| Total formula weight | 37664.74 |
| Authors | Liu, R.J.,Zhou, M.,Wang, E.D. (deposition date: 2013-02-18, release date: 2013-07-31, Last modification date: 2023-11-08) |
| Primary citation | Liu, R.J.,Zhou, M.,Fang, Z.P.,Wang, M.,Zhou, X.L.,Wang, E.D. The tRNA recognition mechanism of the minimalist SPOUT methyltransferase, TrmL Nucleic Acids Res., 41:7828-7842, 2013 Cited by PubMed Abstract: Unlike other transfer RNAs (tRNA)-modifying enzymes from the SPOUT methyltransferase superfamily, the tRNA (Um34/Cm34) methyltransferase TrmL lacks the usual extension domain for tRNA binding and consists only of a SPOUT domain. Both the catalytic and tRNA recognition mechanisms of this enzyme remain elusive. By using tRNAs purified from an Escherichia coli strain with the TrmL gene deleted, we found that TrmL can independently catalyze the methyl transfer from S-adenosyl-L-methionine to and isoacceptors without the involvement of other tRNA-binding proteins. We have solved the crystal structures of TrmL in apo form and in complex with S-adenosyl-homocysteine and identified the cofactor binding site and a possible active site. Methyltransferase activity and tRNA-binding affinity of TrmL mutants were measured to identify residues important for tRNA binding of TrmL. Our results suggest that TrmL functions as a homodimer by using the conserved C-terminal half of the SPOUT domain for catalysis, whereas residues from the less-conserved N-terminal half of the other subunit participate in tRNA recognition. PubMed: 23804755DOI: 10.1093/nar/gkt568 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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