Cloned (Comment) | Organism |
---|---|
gene rmL, recombinant expression of wild-type and mutant enzymes | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.00182 | 0.00537 | cytidine34 in tRNALeuCAA | wild-type tRNALeuCAA and diverse mutants thereof, pH 7.5, 37°C | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
S-adenosyl-L-methionine + cytidine34 in tRNALeuCAA | Escherichia coli | - |
S-adenosyl-L-homocysteine + 2'-O-methylcytidine34 in tRNALeuCAA | - |
? | |
S-adenosyl-L-methionine + cytidine34 in tRNALeuUAA | Escherichia coli | - |
S-adenosyl-L-homocysteine + 2'-O-methylcytidine34 in tRNALeuUAA | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P0AGJ7 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | anticodon stem-loop minihelices with an extension of 2 base pairs are the minimal substrate for EcTrmL methylation. A35 is a key residue for TrmL recognition, while A36-A37-A38 are important either via direct interaction with TrmL or due to the necessity for prior isopentenylation (i6) at A37. In addition, TrmL only methylates pyrimidines but not purine residues at the wobble position, and the 20-O-methylation relies on prior N6-isopentenyladenosine modification at position 37. tRNALeuCAA and tRNALeuUAA isoacceptors are the only two RNA substrates of TrmL. i6A37 is sufficient to restore 20-O-methylation at C34 of EctRNALeuCAA transcripts in vitro. TrmL activity is sensitive to the modified base at position 37, a defect in synthesis of ms2i6A37 at position 37, leads to the loss of 20-O-methylation at C/U 34 at tRNALeuCAA and tRNALeuUAA isoacceptors.16 The isopentenyl modification at position 37 of transcribed tRNALeu is sufficient to recruit TrmL for methylation of nucleotides C34/U34. Although the affinity of i6A-Ts-tRNALeu CAA to EcTrmL is lower than for wild-type EctRNALeuCAA, the i6A modification has a consequent effect on the binding strength of tRNA transcripts for EcTrmL | Escherichia coli | ? | - |
? | |
S-adenosyl-L-methionine + cytidine34 in tRNALeuCAA | - |
Escherichia coli | S-adenosyl-L-homocysteine + 2'-O-methylcytidine34 in tRNALeuCAA | - |
? | |
S-adenosyl-L-methionine + cytidine34 in tRNALeuCAA | diverse mutant variants of tRNALeuCAA, overview | Escherichia coli | S-adenosyl-L-homocysteine + 2'-O-methylcytidine34 in tRNALeuCAA | - |
? | |
S-adenosyl-L-methionine + cytidine34 in tRNALeuUAA | - |
Escherichia coli | S-adenosyl-L-homocysteine + 2'-O-methylcytidine34 in tRNALeuUAA | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | TrmL-catalyzed 2'-O-methylation requires its homodimerization | Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
C/U34 2-O-methyltransferase | - |
Escherichia coli |
Trml | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0073 | 0.2 | cytidine34 in tRNALeuCAA | wild-type tRNALeuCAA and diverse mutants thereof, pH 7.5, 37°C | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
S-adenosyl-L-methionine | - |
Escherichia coli |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme belongs to the SPOUT tRNA MTase superfamily | Escherichia coli |
additional information | TrmL-catalyzed 2'-O-methylation requires its homodimerization. TrmL exhibits a fine-tuned tRNA substrate recognition mechanism. The variable arm of tRNA is not a recognition element for EcTrmL. The anticodon stem of tRNA does not contain recognition elements for EcTrmL | Escherichia coli |
physiological function | TrmL is the prokaryotic methyltransferase that catalyzes the transfer of the methyl group from S-adenosyl-L-methionine to the wobble base of tRNALeuCAA and tRNALeuUAA isoacceptors. This Cm34/Um34 modification affects codon-anticodon interactions and is essential for translational fidelity | Escherichia coli |