glucose 6 phosphatase - ترجمة إلى إنجليزي
![Substrate binding site of G6PD bound to G6P (shown in cream), from [http://www.rcsb.org/pdb/explore.do?structureId=2BHL 2BHL]. Phosphorus is shown in orange. Oxygen atoms of crystallographic waters are shown as red spheres. The conserved 9-peptide sequence of G6PD, and the partially conserved 5-residue sequence of G6PD are shown in cyan and magenta respectively. All other amino acids from G6PD are shown in black. Hydrogen bonding and electrostatic interactions are shown by green dashed lines. All green dashes represent distances of less than 3.7 Å.](https://commons.wikimedia.org/wiki/Special:FilePath/G6PD active site labeled 2.png?width=200 "Substrate binding site of G6PD bound to G6P (shown in cream), from [http://www.rcsb.org/pdb/explore.do?structureId=2BHL 2BHL]. Phosphorus is shown in orange. Oxygen atoms of crystallographic waters are shown as red spheres. The conserved 9-peptide sequence of G6PD, and the partially conserved 5-residue sequence of G6PD are shown in cyan and magenta respectively. All other amino acids from G6PD are shown in black. Hydrogen bonding and electrostatic interactions are shown by green dashed lines. All green dashes represent distances of less than 3.7 Å.")
تعريف
ويكيبيديا
The enzyme glucose 6-phosphatase (EC 3.1.3.9, G6Pase; systematic name D-glucose-6-phosphate phosphohydrolase) catalyzes the hydrolysis of glucose 6-phosphate, resulting in the creation of a phosphate group and free glucose:
- D-glucose 6-phosphate + H2O = D-glucose + phosphate
Glucose is then exported from the cell via glucose transporter membrane proteins. This catalysis completes the final step in gluconeogenesis and therefore plays a key role in the homeostatic regulation of blood glucose levels.
Glucose 6-phosphatase is a complex of multiple component proteins, including transporters for G6P, glucose, and phosphate. The main phosphatase function is performed by the glucose 6-phosphatase catalytic subunit. In humans, there are three isozymes of the catalytic subunit: glucose 6-phosphatase-α, encoded by G6PC; IGRP, encoded by G6PC2; and glucose 6-phosphatase-β, encoded by G6PC3.
Glucose 6-phosphatase-α and glucose 6-phosphatase-β are both functional phosphohydrolases, and have similar active site structure, topology, mechanism of action, and kinetic properties with respect to G6P hydrolysis. In contrast, IGRP has almost no hydrolase activity, and may play a different role in stimulating pancreatic insulin secretion.
