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PROSITE documentation PDOC00954

Purine and other phosphorylases family 2 signature


The following phosphorylases belongs to the same family:

  • Purine nucleoside phosphorylase (EC (PNP) from mammals as well as from some bacteria (gene deoD). This enzyme catalyzes the cleavage of guanosine or inosine to respective bases and sugar-1-phosphate molecules [1].
  • 5'-methylthioadenosine phosphorylase (EC (MTA phosphorylase) from eukaryotes [2].
  • Xanthosine phosphorylase (EC 2.4.2.-) from Escherichia coli (gene xapA). This enzyme can degrade all purine nucleosides except adenosine and deoxyadenosine [3].

This family also includes the following uncharacterized proteins:

  • Yeast hypothetical protein YLR017w.
  • Fission yeast hypothetical protein SpAC16C9.02c.
  • Methanococcus jannaschii hypothetical protein MJ0060.
  • Rhodospirillum rubrum hypothetical protein in petC 3'region.

As a signature pattern, we selected a conserved region in the central part of these enzymes.


It should be noted that most bacterial PNP as well as archaebacterial MTA phosphorylase belong to a different family of phosphorylases (see <PDOC00946>).

Last update:

December 2004 / Pattern and text revised.

Technical section

PROSITE method (with tools and information) covered by this documentation:

PNP_MTAP_2, PS01240; Purine and other phosphorylases family 2 signature  (PATTERN)


1AuthorsEalick S.E. Rule S.A. Carter D.C. Greenhough T.J. Babu Y.S. Cook W.J. Habash J. Helliwell J.R. Stoeckler J.D. Parks R.E. Jr. Chen S.-F. Bugg C.E.
TitleThree-dimensional structure of human erythrocytic purine nucleoside phosphorylase at 3.2 A resolution.
SourceJ. Biol. Chem. 265:1812-1820(1990).
PubMed ID2104852

2AuthorsDella Ragione F. Takabayashi K. Mastropietro S. Mercurio C. Oliva A. Russo G.L. Della Pietra V. Borriello A. Nobori T. Carson D.A. Zappia V.
TitlePurification and characterization of recombinant human 5'-methylthioadenosine phosphorylase: definite identification of coding cDNA.
SourceBiochem. Biophys. Res. Commun. 223:514-519(1996).
PubMed ID8687427

3AuthorsSeeger C. Poulsen C. Dandanell G.
TitleIdentification and characterization of genes (xapA, xapB, and xapR) involved in xanthosine catabolism in Escherichia coli.
SourceJ. Bacteriol. 177:5506-5516(1995).
PubMed ID7559336

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