EC Number |
General Information |
Reference |
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1.14.99.67 | physiological function |
CmlI is a non-heme di-iron enzyme catalyzing N-oxygenation of an amine group, one of the steps in the biosynthesis of the antibiotic chloramphenicol |
-, 760212 |
1.14.99.67 | physiological function |
diferrous CmlI can react with NH2-chloramphenicol species and O2 in either order to form a peroxo-NH2-chloramphenicol intermediate. Peroxo-NH2-chloramphenicol undergoes rapid oxygen transfer to form a diferric CmlI complex with the aryl-hydroxylamine [NH(OH)-chloramphenicol] pathway intermediate. Diferric CmlI-NH(OH)-chloramphenicol undergoes a rapid internal redox reaction to form a differous CmlI-nitroso-chloramphenicol complex. O2 binding results in formation of peroxo-NO-chloramphenicol that converts to differic CmlI-chloramphenicol by enzyme-mediated oxygen atom transfer. There is little dissociation of pathway intermediates as the reaction progresses |
-, 758799 |
1.14.99.67 | physiological function |
during the catalytic cycle substrate N-[(1R,2R)-1-(4-aminophenyl)-1,3-dihydroxypropan-2-yl]-2,2-dichloroacetamide reacts with a long-lived peroxo intermediate to form a NH(OH)-chloramphenicol species and diferric CmlI. Then the NH(OH)-chloramphenicol re-reduces the enzyme diiron cluster, allowing the peroxo species to re-form upon O2 binding, while itself being oxidized to NO-chloramphenicol. Finally, the re-formed peroxo species oxidizes NO-chloramphenicol to chloramphenicol with incorporation of a second O2-derived oxygen atom. The complete six-electron oxidation requires only two exogenous electrons and may occur in one active site |
-, 759397 |
1.14.99.67 | physiological function |
the key oxygenated intermediates in diiron arylamine oxygenases AurF, EC 1.14.99.68, and CmlI, so-called P, are uniformly hydroperoxo species having similar structures rather than the believed peroxo species. A diferric-hydroperoxo P is proposed to be able to promote the arylamine N-oxygenation with highly accessible kinetics |
-, 759400 |