ID 2.1.1.224 DE 23S rRNA (adenine(2503)-C(8))-methyltransferase. CA adenosine(2503) in 23S rRNA + 2 reduced [2Fe-2S]-[ferredoxin] + CA 2 S-adenosyl-L-methionine = 5'-deoxyadenosine + 8-methyladenosine(2503) CA in 23S rRNA + L-methionine + 2 oxidized [2Fe-2S]-[ferredoxin] + CA S-adenosyl-L-homocysteine. CC -!- This enzyme is a member of the 'AdoMet radical' (radical SAM) family. CC -!- S-adenosyl-L-methionine acts as both a radical generator and as the CC source of the appended methyl group. CC -!- Cfr is an plasmid-acquired methyltransferase that protects cells from CC the action of antibiotics. CC -!- The enzyme methylates adenosine at position 2503 of 23S rRNA by a CC radical mechanism, transferring a CH2 group from S-adenosyl-L- CC methionine while retaining the hydrogen at the C-8 position of the CC adenine. CC -!- Cfr first transfers an CH2 group to a conserved cysteine (Cys(338) in CC Staphylococcus aureus), the generated radical from a second CC S-adenosyl-L-methionine then attacks the methyl group, exctracting a CC hydrogen. CC -!- The formed radical forms a covalent intermediate with the adenine CC group of the tRNA. CC -!- The enzyme will also methylate 2-methyladenine produced by the action CC of EC 2.1.1.192. DR A7Z1T2, CFR_BACVZ ; A7FX96, CFR_CLOB1 ; A5I5U3, CFR_CLOBH ; DR B1IL14, CFR_CLOBK ; A7GH77, CFR_CLOBL ; B1KZ37, CFR_CLOBM ; DR A9KK15, CFR_LACP7 ; Q9FBG4, CFR_MAMSC ; Q5WJ42, CFR_SHOC1 ; DR A5HBL2, CFR_STAAU ; A2AXI2, CFR_STAWA ; //