Phosphoadenosine phosphosulphate reductase (IPR002500)

Short name: PAPS_reduct

Overlapping homologous superfamilies

Domain relationships



This domain is found in phosphoadenosine phosphosulphate (PAPS) reductase enzymes or PAPS sulphotransferase. PAPS reductase is part of the adenine nucleotide alpha hydrolases superfamily also including N type ATP PPases and ATP sulphurylases [PMID: 9261082].

A highly modified version of the P loop, the fingerprint peptide of mononucleotide-binding proteins, is present in the active site of the protein, which appears to be a positively charged cleft containing a number of conserved arginine and lysine residues. Although PAPS reductase has no ATPase activity, it shows a striking similarity to the structure of the ATP pyrophosphatase (ATP PPase) domain of GMP synthetase, indicating that both enzyme families have evolved from a common ancestral nucleotide-binding fold [PMID: 9261082].

The enzyme uses thioredoxin as an electron donor for the reduction of PAPS to phospho-adenosine-phosphate (PAP) [PMID: 9261082, PMID: 7588765]. It is also found in NodP nodulation protein P from Rhizobium meliloti (Sinorhizobium meliloti) which has ATP sulphurylase activity (sulphate adenylate transferase) [PMID: 2250719].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0003824 catalytic activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.