| 英文名 |
23S rRNA (adenine2503-C2)-methyltransferase |
| Example Structure |
 |
| 别名 |
Cfr, methyltransferase YfgB/RlmN, radical AdoMet rRNA methyltransferase, radical S-adenosyl-L-methionine enzyme, radical SAM enzyme, RlmN, RlmN methyltransferase, YfgB, YfgB/RlmN |
| EC Number |
2.1.1.192 |
| CAS编号 |
|
| Comments |
Contains an [4Fe-4S] cluster [2]. 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 CH2 group to a conserved cysteine (Cys355 in Escherichia coli) [6], 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 [9]. RlmN is an endogenous enzyme used by the cell to refine functions of the ribosome in protein synthesis [2]. The enzyme methylates adenosine by a radical mechanism with CH2 from the S-adenosyl-L-methionine and retention of the hydrogen at C-2 of adenosine2503 of 23S rRNA. It will also methylate 8-methyladenosine2503 of 23S rRNA. cf. EC 2.1.1.224 [23S rRNA (adenine2503-C8)-methyltransferase]. |
| Cofactor |
iron-sulfur |
| History |
|
| Reactions |
(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. |
