EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
   1.7.1.13 | 7-cyano-7-deazaguanine + 2 NADPH + 2 H+ |
late step in biosynthesis of the modified tRNA nucleoside queuosine |
Bacillus subtilis |
queuine + 2 NADP+ |
- |
? |
| 1.7.1.13 | 7-cyano-7-deazaguanine + 2 NADPH + 2 H+ |
late step in biosynthesis of the modified tRNA nucleoside queuosine |
Escherichia coli |
queuine + 2 NADP+ |
- |
? |
| 1.7.1.13 | 7-cyano-7-deazaguanine + 2 NADPH + 2 H+ |
i.e. preQ0 |
Escherichia coli |
7-aminomethyl-7-deazaguanine + 2 NADP+ |
- |
? |
| 1.7.1.13 | 7-cyano-7-deazaguanine + NADPH + H+ |
- |
Escherichia coli |
queuine + NADP+ + H+ |
- |
? |
| 1.7.1.13 | more |
no substrates: acetonitrile, benzonitrile and benzylcyanide |
Escherichia coli |
? |
- |
? |
| 1.7.1.13 | more |
during catalysis each active site of the dimeric enzyme binds one substrate molecule. NADPH binds independent of the substrate. The PreQ0 binding pocket of the active site is not involved in the binding of NADPH |
Escherichia coli |
? |
- |
? |
| 1.7.1.13 | more |
enzyme is highly specific for substrate preQ0 |
Pectobacterium carotovorum subsp. carotovorum |
? |
- |
? |
| 1.7.1.13 | more |
QueF binds substrate preQ0 in a strongly exothermic process (DeltaH 80.3 kJ/mol) whereby the thioimide adduct is formed with half-of-the-sites reactivity in the homodimeric enzyme. Both steps of preQ0 reduction involve transfer of the 4-pro-R-hydrogen from NADPH. They proceed about 4-7fold more slowly than trapping of the enzyme-bound preQ0 as covalent thioimide and are mainly rate-limiting for the enzyme's kcat |
Escherichia coli |
? |
- |
? |
| 1.7.1.13 | more |
the nitrile to amine conversion proceeds through four major stages: formation of a C-S covalent bond between the substrate and the catalytic cysteine residue to form the thioimidate intermediate, hydride transfer from NADPH to the substrate to generate the thiohemiaminal intermediate, cleavage of the C-S covalent bond to generate the imine intermediate, and second hydride transfer from NADPH to the imine intermediate to generate the final amine product. The free energy barrier for the rate-limiting step, i.e. the second hydride transfer, is20.8 kcal/mol |
Vibrio cholerae O1 |
? |
- |
? |
| 1.7.1.13 | more |
the nitrile to amine conversion proceeds through four major stages: formation of a C-S covalent bond between the substrate and the catalytic cysteine residue to form the thioimidate intermediate, hydride transfer from NADPH to the substrate to generate the thiohemiaminal intermediate, cleavage of the C-S covalent bond to generate the imine intermediate, and second hydride transfer from NADPH to the imine intermediate to generate the final amine product. The free energy barrier for the rate-limiting step, i.e. the second hydride transfer, is20.8 kcal/mol |
Vibrio cholerae O1 ATCC 39315 |
? |
- |
? |
