Oxidoreductases;
Acting on the CH-OH group of donors;
With NAD+ or NADP+ as acceptor
BRITE hierarchy

aurachin B:NAD+ 3-oxidoreductase

aurachin B + NAD+ + H2O = 4-[(2E,6E)-farnesyl]-4-hydroxy-2-methyl-3-oxo-3,4-dihydroquinoline 1-oxide + NADH + H+ (overall reaction) [RN:R11149];
(1a) 4-[(2E,6E)-farnesyl]-3,4-dihydroxy-2-methyl-3,4-dihydroquinoline 1-oxide + NAD+ = 4-[(2E,6E)-farnesyl]-4-hydroxy-2-methyl-3-oxo-3,4-dihydroquinoline 1-oxide + NADH + H+ [RN:R11147];
(1b) aurachin B + H2O = 4-[(2E,6E)-farnesyl]-3,4-dihydroxy-2-methyl-3,4-dihydroquinoline 1-oxide (spontaneous) [RN:R11148]

R11147 R11148 R11149
Reaction

aurachin B [CPD:C21140];
NAD+ [CPD:C00003];
H2O [CPD:C00001];
4-[(2E,6E)-farnesyl]-3,4-dihydroxy-2-methyl-3,4-dihydroquinoline 1-oxide

The enzyme from the bacterium Stigmatella aurantiaca catalyses the final step in the conversion of aurachin C to aurachin B. In vivo the enzyme catalyses the reduction of 4-[(2E,6E)-farnesyl]-4-hydroxy-2-methyl-3-oxo-3,4-dihydroquinoline-1-oxide to form 4-[(2E,6E)-farnesyl]-2-methyl-1-oxo-3,4-dihydroquinoline-3,4-diol (note that the reactions written above proceed from right to left), which then undergoes a spontaneous dehydration to form aurachin B.

EC 1.1.1.394 created 2016

1  [PMID:22907798]