Cloned (Comment) | Organism |
---|---|
- |
Methanococcus maripaludis |
Protein Variants | Comment | Organism |
---|---|---|
C265A | cells expressing the C265A variant show 88% decrease in their 4-thiouridine level. The mutant enzyme contains no detectable amount of persulfide | Methanococcus maripaludis |
C268A | cells expressing the C265A variant contain no 4-thiouridine. The mutant enzyme contains no detectable amount of persulfide | Methanococcus maripaludis |
C348A | cells expressing the C348A variant show 33% decreases in their 4-thiouridine levels. The mutant enzyme contains no detectable amount of persulfide | Methanococcus maripaludis |
C78A | cells expressing the C78A variant show 8% decrease in their 4-thiouridine levels. The C78A variant has similar amounts of persulfide as the wild-type protein | Methanococcus maripaludis |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1 | - |
Sulfide | pH 7.3, 37°C | Methanococcus maripaludis |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
additional information | no spectroscopic features indicative of Fe-S clusters are present | Methanococcus maripaludis |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
sulfide + tRNA-uridine | Methanococcus maripaludis | the enzyme is invoved in biosynthesis of 4-thiouridine in tRNA. 4-Thiouridine, is a modified nucleotide of tRNA that is conserved from bacteria to archaea, where it functions as a sensor for near-UV irradiation | tRNA-4-thiouridine | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Methanococcus maripaludis | Q6LXJ6 | - |
- |
Purification (Comment) | Organism |
---|---|
- |
Methanococcus maripaludis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
sulfide + tRNA-uridine | the enzyme is invoved in biosynthesis of 4-thiouridine in tRNA. 4-Thiouridine, is a modified nucleotide of tRNA that is conserved from bacteria to archaea, where it functions as a sensor for near-UV irradiation | Methanococcus maripaludis | tRNA-4-thiouridine | - |
? | |
sulfide + [tRNACys]-uridine | proposed mechanism: first, a sulfur donor (equivalent of S2-) attacks the Cys265Cys268 disulfide linkage to generate a persulfide on either Cys265 or Cys268, leaving the other Cys as a free thiol. Then, a thiolate derived from deprotonation of the free thiol attacks the bridging sulfur of the persulfide to liberate the terminal sulfur. After donation of the sulfur (in the -2 oxidation state) to form 4-thiouridine, the disulfide (with both sulfurs in the -1 oxidation state) is consequently regenerated. No exogenous electron donor or acceptor is required for the catalytic cycle | Methanococcus maripaludis | [tRNACys]-4-thiouridine | - |
? |
Synonyms | Comment | Organism |
---|---|---|
MMP1354 | locus name | Methanococcus maripaludis |
ThiI | - |
Methanococcus maripaludis |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Methanococcus maripaludis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.3 | - |
assay at | Methanococcus maripaludis |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
additional information | the enzyme requires two conserved Cys residues (Cys265 and Cys268), which are arranged in a CXXC motif in the PP-loop domain, for both in vitro and in vivo activities to generate 4-thiouridine in tRNAs | Methanococcus maripaludis |
General Information | Comment | Organism |
---|---|---|
malfunction | deletion mutant shows no groth defects compared to wild-type, indicating that MMP1354 is not an essential enzyme | Methanococcus maripaludis |
malfunction | deletion of ThiI abolishes the biosynthesis of 4-thiouridine but not of thiamine | Methanococcus maripaludis |
malfunction | MMP1354 complements an Escherichia coli Thi mutant | Methanococcus maripaludis |