Using ATP, hexokinase phosphorylates glucose to produce glucose-6-phosphate (G6P) in the first reaction of glycolysis. Shown here is one subunit of the enzyme. This enzyme has three beta sheets and 18 alpha helices. The active site is made up of 7 residues and is located in a cleft between this subunit's two domains. Upon the binding of hexoses (such as Glucose), hexokinase is induced to assume an active conformation--both domains close together and create the catalytic site. Glucose-6-phosphate (the product of the hexokinase reaction), inhibits hexokinase and binds in a different site than glucose. This site is made up of 8 residues. Since G6P serves to inhibit the enzyme, the hexokinase reaction is regulated via negative feedback. You may wish to manipulate this image yourself: Click and hold the left mouse button to rotate the image about the x and y axes. Rotate about the z axis by pressing the shift key and right mouse button together. The image may be translated along the x and y axes by pressing control and the right mouse button. By pressing shift and the left mouse button together, you may zoom the image in or out. Clicking the right mouse button on the image gives a menu which offers several choices, including spinning the image and changing the appearance and color of the molecule. For more information on this protein, consult: Aleshin, A. et al. (1996) FEBS Letters 391: 9-10.
This enzyme has three beta sheets and 18 alpha helices. The active site is made up of 7 residues and is located in a cleft between this subunit's two domains. Upon the binding of hexoses (such as Glucose), hexokinase is induced to assume an active conformation--both domains close together and create the catalytic site. Glucose-6-phosphate (the product of the hexokinase reaction), inhibits hexokinase and binds in a different site than glucose. This site is made up of 8 residues. Since G6P serves to inhibit the enzyme, the hexokinase reaction is regulated via negative feedback. You may wish to manipulate this image yourself: Click and hold the left mouse button to rotate the image about the x and y axes. Rotate about the z axis by pressing the shift key and right mouse button together. The image may be translated along the x and y axes by pressing control and the right mouse button. By pressing shift and the left mouse button together, you may zoom the image in or out. Clicking the right mouse button on the image gives a menu which offers several choices, including spinning the image and changing the appearance and color of the molecule. For more information on this protein, consult: Aleshin, A. et al. (1996) FEBS Letters 391: 9-10.
The active site is made up of 7 residues and is located in a cleft between this subunit's two domains. Upon the binding of hexoses (such as Glucose), hexokinase is induced to assume an active conformation--both domains close together and create the catalytic site. Glucose-6-phosphate (the product of the hexokinase reaction), inhibits hexokinase and binds in a different site than glucose. This site is made up of 8 residues. Since G6P serves to inhibit the enzyme, the hexokinase reaction is regulated via negative feedback. You may wish to manipulate this image yourself: Click and hold the left mouse button to rotate the image about the x and y axes. Rotate about the z axis by pressing the shift key and right mouse button together. The image may be translated along the x and y axes by pressing control and the right mouse button. By pressing shift and the left mouse button together, you may zoom the image in or out. Clicking the right mouse button on the image gives a menu which offers several choices, including spinning the image and changing the appearance and color of the molecule.
Glucose-6-phosphate (the product of the hexokinase reaction), inhibits hexokinase and binds in a different site than glucose. This site is made up of 8 residues. Since G6P serves to inhibit the enzyme, the hexokinase reaction is regulated via negative feedback.
You may wish to manipulate this image yourself:
For more information on this protein, consult: Aleshin, A. et al. (1996) FEBS Letters 391: 9-10.