Protein Variants | Comment | Organism |
---|---|---|
D136N | D136N mutant strain accumulates larger amounts of 30S and 50S ribosomal subunits than wild-type strains under nonstringent salt conditions, and has a significant amount of 40S ribosomal particles under stringent salt conditions | Escherichia coli |
D136N | mutation leads to slight decrease in kcat value | Escherichia coli |
D20A | mutation leads to slight decrease in kcat value | Escherichia coli |
F166A | decrease in S-adenosyl-L-methionine binding affinity and/or the presence of a certain amount of an inactive yet stably folded RrmJ mutant species | Escherichia coli |
F37A/L39A | mutant strain shows ribosome profiles that are indistinguishable from wild-type ribosome profile | Escherichia coli |
additional information | extensive site-directed mutagenesis of the residues conserved in RrmJ and characterization of the mutant proteins both in vivo and in vitro | Escherichia coli |
Q67A/Y68A | mutant strain shows ribosome profiles that are indistinguishable from wild-type ribosome profile | Escherichia coli |
R32A/R34A | R32A/R34A mutant strain accumulates larger amounts of 30S and 50S ribosomal subunits than wild-type strains under nonstringent salt conditions, and has a significant amount of 40S ribosomal particles under stringent salt conditions | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | changes in apparent Km-values for 50S subunit binding in RrmJ mutant proteins | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
S-adenosyl-L-methionine + uridine2552 in 23S rRNA | Escherichia coli | the enzyme is responsible for the 2'-O methylation of the universally conserved U2552 in the A loop of 23S rRNA | S-adenosyl-L-homocysteine + 2'-O-methyluridine2552 in 23S rRNA | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | A0A140N5X9 | - |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
S-adenosyl-L-methionine + uridine2552 in 23S rRNA = S-adenosyl-L-homocysteine + 2'-O-methyluridine2552 in 23S rRNA | mechanism, based on modeling studies and the structure of the 50S ribosome, a two-step model is proposed where the A loop undocks from the tightly packed 50S ribosomal subunit, allowing RrmJ to gain access to the substrate nucleotide U2552, and where U2552 undergoes base flipping, allowing the enzyme to methylate the 2'-O position of the ribose | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
S-adenosyl-L-methionine + uridine2552 in 23S rRNA | the enzyme is responsible for the 2'-O methylation of the universally conserved U2552 in the A loop of 23S rRNA | Escherichia coli | S-adenosyl-L-homocysteine + 2'-O-methyluridine2552 in 23S rRNA | - |
? | |
S-adenosyl-L-methionine + uridine2552 in 23S rRNA | the isolated unmodified A loop serves as the minimal methylation substrate of wild-type RrmJ in vitro. 50S ribosomal subunits prepared from the rrmJ deletion strain appear to serve as substrates for RrmJ in vitro, while naked 23S rRNA or 40S ribosomal particles that are prepared from the rrmJ deletion strain are not methylated by purified RrmJ. This finding suggests that either the correct folding of the 23S rRNA or additional protein-protein interactions are necessary for the substrate recognition. A positively charged, highly conserved ridge in RrmJ appears to play a significant role in 23S rRNA binding and methylation. A structural model is provided of how the A loop of the 23S rRNA binds to RrmJ. Based on modeling studies and the structure of the 50S ribosome, a two-step model is proposed where the A loop undocks from the tightly packed 50S ribosomal subunit, allowing RrmJ to gain access to the substrate nucleotide U2552, and where U2552 undergoes base flipping, allowing the enzyme to methylate the 2'-O position of the ribose | Escherichia coli | S-adenosyl-L-homocysteine + 2'-O-methyluridine2552 in 23S rRNA | - |
? |
Synonyms | Comment | Organism |
---|---|---|
23S rRNA methyltransferase | - |
Escherichia coli |
FTSJ | - |
Escherichia coli |
RrmJ | - |
Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | changes in apparent kcat-values for 50S subunit binding in RrmJ mutant proteins | Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
S-adenosyl-L-methionine | - |
Escherichia coli |
General Information | Comment | Organism |
---|---|---|
metabolism | absence of functional RrmJ causes the cellular accumulation of the individual ribosomal subunits at the expense of the functional 70S ribosomes | Escherichia coli |
physiological function | the 23S rRNA modification is critical for ribosome stability | Escherichia coli |