5'-nucleotidases (EC 18.104.22.168)  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 22.214.171.124), 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 126.96.36.199) (ATP-diphosphohydrolase) . 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
December 2004 / Pattern and text revised.
PROSITE methods (with tools and information) covered by this documentation:
5'-Nucleotidase: molecular structure and functional aspects.
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