Accepted Name |
ribonucleoside-triphosphate reductase (thioredoxin)
|
Alternative Name(s) |
ribonucleotide reductase |
Reaction catalysed |
[thioredoxin]-disulfide + a 2'-deoxyribonucleoside 5'-triphosphate + H2O <=> [thioredoxin]-dithiol + a ribonucleoside 5'-triphosphate |
Comment(s) |
- The enzyme, characterized from the bacterium Lactobacillus
leichmannii, is similar to class II ribonucleoside-diphosphate
reductase (cf. EC 1.17.4.1); however, it is specific for the
triphosphate versions of its substrates.
- The enzyme contains an adenosylcobalamin cofactor that is involved in
generation of a transient thiyl (sulfanyl) radical on a cysteine
residue.
- This radical attacks the substrate, forming a ribonucleotide
3'-radical, followed by water loss to form a ketyl (alpha-oxoacyl)
radical.
- The ketyl radical is reduced to 3'-keto-deoxynucleotide concomitant
with formation of a disulfide anion radical between two cysteine
residues.
- A proton-coupled electron-transfer from the disulfide radical to the
substrate generates a 3'-deoxynucleotide radical, and the the final
product is formed when the hydrogen atom that was initially removed
from the 3'-position of the nucleotide by the thiyl radical is
returned to the same position.
- The disulfide bridge is reduced by the action of thioredoxin. cf.
EC 1.1.98.6.
|
Cross-references |
BRENDA | 1.17.4.2 |
EC2PDB | 1.17.4.2 |
ExplorEnz | 1.17.4.2 |
PRIAM enzyme-specific profiles | 1.17.4.2 |
KEGG Ligand Database for Enzyme Nomenclature | 1.17.4.2 |
IUBMB Enzyme Nomenclature | 1.17.4.2 |
IntEnz | 1.17.4.2 |
MEDLINE | Find literature relating to 1.17.4.2 |
MetaCyc | 1.17.4.2 |
Rhea expert-curated reactions | 1.17.4.2 |
UniProtKB/Swiss-Prot |
Q54CW7, RTPR_DICDI | Q2PDF6, RTPR_EUGGR | Q5FMX8, RTPR_LACAC |
Q1G7W2, RTPR_LACDA | Q04CQ7, RTPR_LACDB | Q041L3, RTPR_LACGA |
A8YW74, RTPR_LACH4 | Q59490, RTPR_LACLE | Q035U1, RTPR_LACP3 |
Q03PB4, RTPR_LEVBA | A6Q367, RTPR_NITSB | Q857H2, VG50_BPMB2 |
O64240, VG50_BPMD2 | Q05262, VG50_BPML5 |
|
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