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PROSITE documentation PDOC00627

5'-nucleotidase signatures


5'-nucleotidases (EC [1] are enzymes that catalyze the hydrolysis of phosphate esterified at carbon 5' of the ribose and deoxyribose portions of nucleotide molecules. 5'-nucleotidase is a ubiquitous enzyme found in a wide variety of species and which occurs in different cellular locations. The sequences of the following 5'-nucleotidases are currently known:

  • Extracellular 5'-nucleotidase from mammals and electric ray. This isozyme is a homodimeric disulfide-bonded glycoprotein attached to the membrane by a GPI-anchor. It requires zinc for its activity
  • Vibrio parahaemolyticus 5'-nucleotidase (gene nutA). This isozyme is bound to the membrane by a lipid chain. NutA requires chloride and magnesium ions for its activity. It is involved in degrading extracellular 5'-nucleotides for nutritional needs.
  • Periplasmic bacterial 5'-nucleotidase (gene ushA). This enzyme, also known as UDP-sugar hydrolase (EC, can degrade UDP-glucose and other nucleotide diphosphate sugars. It produces sugar-1-phosphate which can then be used by the cell. UshA seems to require cobalt for its activity.

5'-nucleotidases are evolutionary related to the following enzyme:

  • Periplasmic bacterial 2',3'-cyclic-nucleotide 2'-phosphodiesterase (EC 3.1. 4.16) (gene cpdB). This bifunctional enzyme catalyzes two consecutive reactions: it first converts 2',3'-cyclic-nucleotide to 3'-nucleotide and then acts as a 3'-nucleotidase.
  • Mosquito apyrase (EC (ATP-diphosphohydrolase) [2]. This enzyme catalyzes the hydrolysis of ATP into AMP and facilitates hematophagy by preventing ADP-dependent platelet aggregation in the host.

All these proteins share a number of regions of sequence similarity, of which we selected two as signature patterns. Both regions are located in the N-terminal section of these enzymes. The second pattern contains a perfectly conserved pentapeptide.

Last update:

December 2004 / Pattern and text revised.

Technical section

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

5_NUCLEOTIDASE_1, PS00785; 5'-nucleotidase signature 1  (PATTERN)

5_NUCLEOTIDASE_2, PS00786; 5'-nucleotidase signature 2  (PATTERN)


1AuthorsZimmermann H.
Title5'-Nucleotidase: molecular structure and functional aspects.
SourceBiochem. J. 285:345-365(1992).
PubMed ID1637327

2AuthorsChampagne D.E., Smartt C.T., Ribeiro J.M.C., James A.A.
TitleThe salivary gland-specific apyrase of the mosquito Aedes aegypti is a member of the 5'-nucleotidase family.
SourceProc. Natl. Acad. Sci. U.S.A. 92:694-698(1995).
PubMed ID7846038

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