Transferases;
Transferring one-carbon groups;
Methyltransferases
BRITE hierarchy

S-adenosyl-L-methionine:23S rRNA (adenine2503-C2)-methyltransferase

(1) 2 S-adenosyl-L-methionine + adenine2503 in 23S rRNA + 2 reduced [2Fe-2S] ferredoxin = S-adenosyl-L-homocysteine + L-methionine + 5'-deoxyadenosine + 2-methyladenine2503 in 23S rRNA + 2 oxidized [2Fe-2S] ferredoxin;
(2) 2 S-adenosyl-L-methionine + adenine37 in tRNA + 2 reduced [2Fe-2S] ferredoxin = S-adenosyl-L-homocysteine + L-methionine + 5'-deoxyadenosine + 2-methyladenine37 in tRNA + 2 oxidized [2Fe-2S] ferredoxin

S-adenosyl-L-methionine [CPD:C00019];
adenine2503 in 23S rRNA;
reduced [2Fe-2S] ferredoxin [CPD:C22150];
adenine37 in tRNA

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].

EC 2.1.1.192 created 2010, modified 2011, modified 2014