Enzyme - 3'(2'),5'-bisphosphate nucleotidase

Alternative Name(s)
  • 3'(2'),5'-bisphosphonucleoside 3'(2')-phosphohydrolase.
  • Phosphoadenylate 3'-nucleotidase.
  • DPNPase.
  • 3'-phosphoadenylylsulfate 3'-phosphatase.

Catalytic Activity

denosine 3',5'-bisphosphate + H2O = AMP + phosphate


There are no Cofactors for this Enzyme

Reaction Mechanism

    Catalyses the removal of the 3'-phosphate from adenosine 5'-phosphosulfate to reform AMP. This reaction helps drive the sulfur incorporation cycle for pathways such as methionine biosynthesis. Sensitivity of this essential enzyme to sodium and other metal ions results is responsible for characterisation of this enzyme as a salt tolerance protein [PMID:10205895]. Some members of this family are active also as inositol 1-monophosphatase.

    A water molecule bound to the first site magnesium ion is activated through a proton relay with Asp49 and Thr147. It then attacks the 3'-phosphate group, eliminating the product phosphate and a negatively charged intermediate which subsequently is reprotonated from bulk solvent via a proton relay involving the second ribose hydroxyl group and a water bound to the second magnesium site.
    Catalytic Residues
    AA Uniprot Uniprot Resid PDB PDB Resid
    Asp P32179 142 1qgx 142
    Ile P32179 144 1qgx 144
    Asp P32179 145 1qgx 145
    Glu P32179 72 1qgx 72
    Asp P32179 49 1qgx 49
    Thr P32179 147 1qgx 147
    Asp P32179 294 1qgx 294
    Step Components

    overall product formed, proton transfer, overall reactant used, bimolecular nucleophilic addition, native state of enzyme regenerated, inferred reaction step, proton relay

    Step 1.

    Asp49 activates the catalytic water through Thr147. The activated species then initiates a nucleophilic attack on the magnesium bound phosphate, eliminating it from the diphosphate substrate.

    Step 2.

    The intermediate is reprotonated from the bulk solvent via a proton relay through the other ribose sugar, the second magnesium bound water and thence bulk solvent.

    Step 3.

    Inferred return step.


    The products of the reaction.

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Protein name Organism
3'(2'),5'-bisphosphate nucleotidase Fission yeast
Putative PAP-specific phosphatase, mitochondrial Mouse-ear cress
3'(2'),5'-bisphosphate nucleotidase 2 Yeast
Golgi-resident adenosine 3',5'-bisphosphate 3'-phosphatase Mouse
3'(2'),5'-bisphosphate nucleotidase 1 Human