Crystallization (Comment) | Organism |
---|---|
purified enzyme mutant D170A and Y78A in complex with S-adenosyl-L-methionine, hanging drop vapor diffusion method, mixing of 10 mg/ml protein in 20 mM Tris-HCl buffer, pH 8.0, 100 mM KCl, and 2mM S-adenosyl-L-methionine with reservoir solution containing 2.4 M ammonium sulfate and 10% v/v isopropanol for mutant D170A and 2.1 M ammonium sulfate and 8% v/v isopropanol for mutant Y78A, X-ray diffraction structure determination and analysis at 3.1 A and 2.6 A resolution, respectively. Crystallization assays of enzyme TrmI Y194A lead to poorly diffracting crystals | Thermus thermophilus |
Protein Variants | Comment | Organism |
---|---|---|
D170A | site-directed mutagenesis, mutation of a conserved active site residue | Thermus thermophilus |
Y194A | site-directed mutagenesis, crystallization assays of TrmI Y194A lead to poorly diffracting crystals | Thermus thermophilus |
Y78A | site-directed mutagenesis, mutation of a conserved active site residue. The structure of TrmI Y78A catalytic domain is unmodified regarding the binding of the SAM co-factor and the conformation of residues potentially interacting with the substrate adenine, as compared to the wild-type structure. The structure of the D170A mutant shows a flexible active site with one loop occupying in part the place of the co-factor and the second loop moving at the entrance to the active site | Thermus thermophilus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
S-adenosyl-L-methionine + adenine58 in tRNA | Thermus thermophilus | - |
S-adenosyl-L-homocysteine + N1-methyladenine58 in tRNA | - |
? | |
S-adenosyl-L-methionine + adenine58 in tRNA | Thermus thermophilus DSM 7039 | - |
S-adenosyl-L-homocysteine + N1-methyladenine58 in tRNA | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Thermus thermophilus | Q8GBB2 | HB27 | - |
Thermus thermophilus DSM 7039 | Q8GBB2 | HB27 | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
S-adenosyl-L-methionine + adenine58 in tRNA = S-adenosyl-L-homocysteine + N1-methyladenine58 in tRNA | two possible mechanisms for methyl transfer: (A) with deprotonation of the amino exocyclic group of the adenine ring and via the intermediate imino tautomer of m1A, (B) by direct transfer of the methyl, without intermediate, detailed overview | Thermus thermophilus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
S-adenosyl-L-methionine + adenine58 in tRNA | - |
Thermus thermophilus | S-adenosyl-L-homocysteine + N1-methyladenine58 in tRNA | - |
? | |
S-adenosyl-L-methionine + adenine58 in tRNA | - |
Thermus thermophilus DSM 7039 | S-adenosyl-L-homocysteine + N1-methyladenine58 in tRNA | - |
? |
Synonyms | Comment | Organism |
---|---|---|
TrmI | - |
Thermus thermophilus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
S-adenosyl-L-methionine | - |
Thermus thermophilus |
General Information | Comment | Organism |
---|---|---|
additional information | recognition of tRNA substrate and structure of the catalytic pocket, overview. The flexibility of the N-terminal domain that is probably important to bind tRNA. Role of residue Y78 in stabilizing the conformation of the A58 ribose needed to hold substrate adenosine in the active site, and central role of residue D170 in binding the amino moiety of S-adenosyl-L-methionine and the exocyclic amino group of adenine | Thermus thermophilus |