Enolase catalyzes the formation of phosphoenolpyruvate (PEP) through the dehydration of 2-phosphoglycerate. This reaction is important because it rearranges the substrate into a form that will yield more potential energy upon hydrolysis. Shown here, enolase is a dimer of identical subunits. It is easier to understand the enolase reaction when focusing on only one subunit. There are 20 alpha helices in each subunit and four beta sheets. There are two 2-stranded parallel sheets, One 3-stranded antiparallel sheet, and a 6-stranded mixed sheet. When phosphoglycerate binds, it forms a hydrogen bond with Lys396. This residue, along with 2 Mg2+ ions, stabilizes the negatively charged reaction intermediate. The enolase reaction occurs in two steps. First an enzymatic base (Lys345) abstracts a proton 2-PGA's C-2-creating a carbanion intermediate. Then, an acid catalyst residue (most likely Glu211) removes an OH from the intermediates hydroxymethyl group. This produces PEP. 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.
Shown here, enolase is a dimer of identical subunits. It is easier to understand the enolase reaction when focusing on only one subunit. There are 20 alpha helices in each subunit and four beta sheets. There are two 2-stranded parallel sheets, One 3-stranded antiparallel sheet, and a 6-stranded mixed sheet. When phosphoglycerate binds, it forms a hydrogen bond with Lys396. This residue, along with 2 Mg2+ ions, stabilizes the negatively charged reaction intermediate. The enolase reaction occurs in two steps. First an enzymatic base (Lys345) abstracts a proton 2-PGA's C-2-creating a carbanion intermediate. Then, an acid catalyst residue (most likely Glu211) removes an OH from the intermediates hydroxymethyl group. This produces PEP. 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.
There are 20 alpha helices in each subunit and four beta sheets. There are two 2-stranded parallel sheets, One 3-stranded antiparallel sheet, and a 6-stranded mixed sheet. When phosphoglycerate binds, it forms a hydrogen bond with Lys396. This residue, along with 2 Mg2+ ions, stabilizes the negatively charged reaction intermediate. The enolase reaction occurs in two steps. First an enzymatic base (Lys345) abstracts a proton 2-PGA's C-2-creating a carbanion intermediate. Then, an acid catalyst residue (most likely Glu211) removes an OH from the intermediates hydroxymethyl group. This produces PEP. 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.
When phosphoglycerate binds, it forms a hydrogen bond with Lys396. This residue, along with 2 Mg2+ ions, stabilizes the negatively charged reaction intermediate. The enolase reaction occurs in two steps. First an enzymatic base (Lys345) abstracts a proton 2-PGA's C-2-creating a carbanion intermediate. Then, an acid catalyst residue (most likely Glu211) removes an OH from the intermediates hydroxymethyl group. This produces PEP. 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.
The enolase reaction occurs in two steps. First an enzymatic base (Lys345) abstracts a proton 2-PGA's C-2-creating a carbanion intermediate. Then, an acid catalyst residue (most likely Glu211) removes an OH from the intermediates hydroxymethyl group. This produces PEP. 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.
Then, an acid catalyst residue (most likely Glu211) removes an OH from the intermediates hydroxymethyl group. This produces PEP.
You may wish to manipulate this image yourself: