Glucose-1-phosphate adenylyltransferase

In enzymology, a glucose-1-phosphate adenylyltransferase (EC 2.7.7.27) is an enzyme that catalyzes the chemical reaction

glucose-1-phosphate adenylyltransferase
Glucose-1-phosphate adenylyltransferase tetramer, Rhizobium radiobacter
Identifiers
EC no.2.7.7.27
CAS no.9027-71-8
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
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NCBIproteins
ATP + alpha-D-glucose 1-phosphate diphosphate + ADP-glucose

Thus, the two substrates of this enzyme are ATP and alpha-D-glucose 1-phosphate, whereas its two products are diphosphate and ADP-glucose.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is ATP:alpha-D-glucose-1-phosphate adenylyltransferase. Other names in common use include ADP glucose pyrophosphorylase, glucose 1-phosphate adenylyltransferase, adenosine diphosphate glucose pyrophosphorylase, adenosine diphosphoglucose pyrophosphorylase, ADP-glucose pyrophosphorylase, ADP-glucose synthase, ADP-glucose synthetase, ADPG pyrophosphorylase, ADP:alpha-D-glucose-1-phosphate adenylyltransferase and AGPase.

This enzyme participates in starch and sucrose metabolism and glycogen metabolism in bacteria. The rate limiting step in their synthesis appears to be regulated at the level of this enzyme. In many species glycolytic intermediates act to stimulate enzyme activity while AMP or phosphate inhibit enzyme activity.

In contrast, in many animals, the synthesis of alpha 1,4 glucans (glycogen) uses UDP-glucose as a glucose donor. In this case, the regulated step is instead the glycosyl transferase.

Structural studies

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As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 1YP2, 1YP3, and 1YP4.

References

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  • Ghosh HP, Preiss J (1966). "Adenosine diphosphate glucose pyrophosphorylase. A regulatory enzyme in the biosynthesis of starch in spinach leaf chloroplasts". J. Biol. Chem. 241 (19): 4491–504. doi:10.1016/S0021-9258(18)99747-4. PMID 5922972.
  • Shen L; Preiss J (1965). "Biosynthesis of bacterial glycogen. I. Purification and properties of the adenosine diphosphoglucose pyrophosphorylase of Arthrobacter species NRRL B1973". J. Biol. Chem. 240 (6): 2334–2340. doi:10.1016/S0021-9258(18)97327-8. PMID 14304834.