Oxidoreductases;
Acting on the CH-OH group of donors;
With other, known, physiological acceptors
BRITE hierarchy

ribonucleoside-5'-triphosphate:formate 2'-oxidoreductase

ribonucleoside 5'-triphosphate + formate = 2'-deoxyribonucleoside 5'-triphosphate + CO2 + H2O [RN:R11592]

R11592 > R11633 R11634 R11635 R11636
Reaction

ribonucleoside 5'-triphosphate [CPD:C03802];
formate [CPD:C00058]

The enzyme, which is expressed in the bacterium Escherichia coli during anaerobic growth, contains an iron sulfur center. The active form of the enzyme contains an oxygen-sensitive glycyl (1-amino-2-oxoethan-1-yl) radical that is generated by the activating enzyme NrdG via chemistry involving S-adenosylmethionine (SAM) and a [4Fe-4S] cluster. The glycyl radical is involved in generation of a transient thiyl (sulfanyl) radical on a cysteine residue, which attacks the substrate, forming a ribonucleotide 3'-radical, followed by water loss to form a ketyl (alpha-oxoalkyl) radical. The ketyl radical gains an electron from a cysteine residue and a proton from formic acid, forming 3'-keto-deoxyribonucleotide and generating a thiosulfuranyl (1lambda4-disulfan-1-yl) radical bridge between methionine and cysteine residues. Oxidation of formate by the thiosulfuranyl radical results in the release of CO2 and regeneration of the thiyl radical. cf. EC 1.17.4.1, ribonucleoside-diphosphate reductase and EC 1.17.4.2, ribonucleoside-triphosphate reductase (thioredoxin).

EC 1.1.98.6 created 2017