CATH Classification
| Level | CATH Code | Description |
|---|---|---|
|
3 | Alpha Beta |
|
3.20 | Alpha-Beta Barrel |
|
3.20.20 | TIM Barrel |
|
3.20.20.70 | Aldolase class I |
Domain Context
CATH Clusters
| Superfamily | Aldolase class I |
| Functional Family | Dual-specificity RNA methyltransferase RlmN |
Enzyme Information
| 2.1.1.192 |
23S rRNA (adenine(2503)-C(2))-methyltransferase.
based on mapping to UniProt P36979
(1) 2 S-adenosyl-L-methionine + adenine(2503) in 23S rRNA + 2 reduced [2Fe-2S] ferredoxin = S-adenosyl-L-homocysteine + L-methionine + 5'-deoxyadenosine + 2-methyladenine(2503) in 23S rRNA + 2 oxidized [2Fe- 2S] ferredoxin. (2) 2 S-adenosyl-L-methionine + adenine(37) in tRNA + 2 reduced [2Fe-2S] ferredoxin = S-adenosyl-L-homocysteine + L-methionine + 5'-deoxyadenosine + 2-methyladenine(37) in tRNA + 2 oxidized [2Fe-2S] ferredoxin.
-!- This enzyme is a member of the 'AdoMet radical' (radical SAM) family. -!- S-adenosyl-L-methionine acts as both a radical generator and as the source of the appended methyl group. -!- RlmN first transfers an CH(2) group to a conserved cysteine (Cys(355) in Escherichia coli), the generated radical from a second S-adenosyl- L-methionine then attacks the methyl group, exctracting a hydrogen. -!- The formed radical forms a covalent intermediate with the adenine group of the tRNA. -!- RlmN is an endogenous enzyme used by the cell to refine functions of the ribosome in protein synthesis. -!- The enzyme methylates adenosine by a radical mechanism with CH(2) from the S-adenosyl-L-methionine and retention of the hydrogen at C-2 of adenosine(2503) of 23S rRNA. -!- It will also methylate 8-methyladenosine(2503) of 23S rRNA (cf. EC 2.1.1.224).
|
UniProtKB Entries (1)
| P36979 |
RLMN_ECOLI
Escherichia coli K-12
Dual-specificity RNA methyltransferase RlmN
|
PDB Structure
| PDB | 5HR7 |
| External Links | |
| Method | X-RAY DIFFRACTION |
| Organism | |
| Primary Citation |
Crystallographic capture of a radical S-adenosylmethionine enzyme in the act of modifying tRNA.
Science
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