Phosphoglucoisomerase: Difference between revisions

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'''Phosphoglucoisomerase''' (alternatively known as '''phosphoglucose isomerase''' or '''Glucose-6-phosphate isomerase''') are a group of enzymes of the isomerase family ([http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.9 EC 5.3.1.9]), so named for their main function in glycolysis and gluconeogenesis. In both these pathways phosphoglucose isomerase (PGI) is used to inter-convert glucose-6-phosphate and fructose 6-phosphate, reaction driven by the relative concentrations of these sugars in the cytoplasmic matrix of the cell.

'''Phosphoglucoisomerase''' (alternatively known as '''phosphoglucose isomerase''' or '''Glucose-6-phosphate isomerase''') are a group of enzymes of the isomerase family ([http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.9 EC 5.3.1.9]), so named for their main function in glycolysis and gluconeogenesis. In both these pathways phosphoglucose isomerase (PGI) is used to inter-convert glucose-6-phosphate and fructose 6-phosphate, reaction driven by the relative concentrations of these sugars in the cytoplasmic matrix of the cell <ref>PMID:11371164</ref>.

Phosphoglucoisomerase is also know for a list of activities outside the cells:

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=='''Structure'''==

[[Image:Align.jpg|thumb|left|'''Figure 1.''' Multiple alignment PGI - ''Geobacillus stearothermophilus'' (white),'' Homo sapiens'' (pink), ''Oryctolagus cuniculus'' (blue)]]

[[Image:Align.jpg|thumb|left|'''Figure 1.''' Multiple alignment PGI - ''Geobacillus stearothermophilus'' (white),'' Homo sapiens'' (pink), ''Oryctolagus cuniculus'' (blue)<ref> UCSF Chimera--a visualization system for exploratory research and analysis. Pettersen EF, Goddard TD, Huang CC, Couch GS, Greenblatt DM, Meng EC, Ferrin TE. J Comput Chem. 2004 Oct;25(13):1605-12. </ref>]]

Phosphoglucose isomerase exists in the cell usually as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Dimer/1'>homodimer</scene>, nevertheless outside of the cell, it has been isolated as <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Monomer/1'>monomeric</scene> structure. PGI has essentially an identical fold in all of the characterized species (see '''Figure 1'''). The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Sec_struct/1'>secondary structure</scene> of phosphoglucose isomerase is charaterized by an αβα conformation, on each of its two domains. The smaller domain is characterized by 5 parallel β-sheets, while the larger domain if formed out of 6 parallel/antiparallel β-sheets. Furthermore, another ~~charateristical~~ trait is a residue extension at the C-terminus, which wraps around the other monomer in the dimeric conformation

Phosphoglucose isomerase exists in the cell usually as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Dimer/1'>homodimer</scene>, nevertheless outside of the cell, it has been isolated as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Monomer/1'>monomeric</scene> structure. PGI has essentially an identical fold in all of the characterized species (see '''Figure 1'''). The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Sec_struct/1'>secondary structure</scene> of phosphoglucose isomerase is charaterized by an αβα conformation, on each of its two domains. The smaller domain is characterized by 5 parallel β-sheets, while the larger domain if formed out of 6 parallel/antiparallel β-sheets. Furthermore, another characteristic trait is a residue extension at the C-terminus, which wraps around the other monomer in the dimeric conformation.

Phosphoglucose isomerase has a molecular mass of proximately 55 kDa.

'''Active Site''' - Mammalian PGI shows a degree of <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Conservation2/1'>conservation</scene> ( dark red ~~represent~~ highly conserved regions - dark blue ~~regions that are~~ variable) of about 90 %. The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Active_site/1'>active site</scene> is the region with highest observed conservation, with a number of residues that are crucial in the mechanism of the enzyme (Lys210, Gln353, Glu357, Gln511, Lys518, His388b).

'''Active Site''' - Mammalian PGI shows a degree of <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Conservation2/1'>conservation</scene> ( dark red for highly conserved regions - dark blue for variable reigions) of about 90 %. The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Active_site/1'>active site</scene> is the region with highest observed conservation, with a number of residues that are crucial in the mechanism of the enzyme (Lys210, Gln353, Glu357, Gln511, Lys518, His388b).

[[Image:Active_site_movement.jpg|thumb|left|'''Figure 2.''' Substrate induced movement]]

Another characteristic of phosphoglucose isomerase is that binding of substrate at the active site, induces a movement in the conformation of the enzyme. This can be seen in '''Figure 2''' as change in the position of an α helix.

Another characteristic of phosphoglucose isomerase is that binding of substrate at the active site, induces a movement in the conformation of the enzyme. This can be seen in Figure 2 as change in the position of an α helix.

~~[[Image:Active_site_movement.jpg|thumb|left|'''Figure 2.''' Substrate induced movement]]~~

=='''Mechanism'''==

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* Crystal Structure of human phosphoglucose isomerase (PDB=[[1iat]]~~<ref>PMID:11371164</ref>~~)

* Crystal Structure of human phosphoglucose isomerase (PDB=[[1iat]])

* Crystal Structure of rabbit phosphoglucose isomerase complexed fructose 6-phosphate (PDB=[[1hox]]<ref>PMID:11425306</ref>)

Phosphoglucoisomerase: Difference between revisions

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@@ Line 1: / Line 1: @@
 <applet load="1iat" size="300" color="white" frame="true" align="right" caption="Human phosphoglucose isomerase (1IAT)" />
-'''Phosphoglucoisomerase''' (alternatively known as '''phosphoglucose isomerase''' or '''Glucose-6-phosphate isomerase''') are a group of enzymes of the isomerase family ([http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.9 EC 5.3.1.9]), so named for their main function in glycolysis and gluconeogenesis. In both these pathways phosphoglucose isomerase (PGI) is used to inter-convert glucose-6-phosphate and fructose 6-phosphate, reaction driven by the relative concentrations of these sugars in the cytoplasmic matrix of the cell.
+'''Phosphoglucoisomerase''' (alternatively known as '''phosphoglucose isomerase''' or '''Glucose-6-phosphate isomerase''') are a group of enzymes of the isomerase family ([http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.9 EC 5.3.1.9]), so named for their main function in glycolysis and gluconeogenesis. In both these pathways phosphoglucose isomerase (PGI) is used to inter-convert glucose-6-phosphate and fructose 6-phosphate, reaction driven by the relative concentrations of these sugars in the cytoplasmic matrix of the cell <ref>PMID:11371164</ref>.
 Phosphoglucoisomerase is also know for a list of activities outside the cells:
@@ Line 11: / Line 11: @@
 =='''Structure'''==
 <applet load="1hox" size="400" color="white" frame="true" align="right" caption="Phosphoglucose isomerase" />
-[[Image:Align.jpg|thumb|left|'''Figure 1.''' Multiple alignment PGI - ''Geobacillus stearothermophilus'' (white),'' Homo sapiens'' (pink), ''Oryctolagus cuniculus'' (blue)]]
+[[Image:Align.jpg|thumb|left|'''Figure 1.''' Multiple alignment PGI - ''Geobacillus stearothermophilus'' (white),'' Homo sapiens'' (pink), ''Oryctolagus cuniculus'' (blue)<ref>    UCSF Chimera--a visualization system for exploratory research and analysis. Pettersen EF, Goddard TD, Huang CC, Couch GS, Greenblatt DM, Meng EC, Ferrin TE. J Comput Chem. 2004 Oct;25(13):1605-12. </ref>]]
-Phosphoglucose isomerase exists in the cell usually as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Dimer/1'>homodimer</scene>, nevertheless outside of the cell, it has been isolated as <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Monomer/1'>monomeric</scene> structure. PGI has essentially an identical fold in all of the characterized species (see '''Figure 1'''). The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Sec_struct/1'>secondary structure</scene> of phosphoglucose isomerase is charaterized by an αβα conformation, on each of its two domains. The smaller domain is characterized by 5 parallel β-sheets, while the larger domain if formed out of 6 parallel/antiparallel β-sheets. Furthermore, another charateristical trait is a residue extension at the C-terminus, which wraps around the other monomer in the dimeric conformation
+Phosphoglucose isomerase exists in the cell usually as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Dimer/1'>homodimer</scene>, nevertheless outside of the cell, it has been isolated as a <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Monomer/1'>monomeric</scene> structure. PGI has essentially an identical fold in all of the characterized species (see '''Figure 1'''). The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Sec_struct/1'>secondary structure</scene> of phosphoglucose isomerase is charaterized by an αβα conformation, on each of its two domains. The smaller domain is characterized by 5 parallel β-sheets, while the larger domain if formed out of 6 parallel/antiparallel β-sheets. Furthermore, another characteristic trait is a residue extension at the C-terminus, which wraps around the other monomer in the dimeric conformation.
 Phosphoglucose isomerase has a molecular mass of proximately 55 kDa.
-'''Active Site''' - Mammalian PGI shows a degree of <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Conservation2/1'>conservation</scene> ( dark red represent highly conserved regions - dark blue regions that are variable) of about 90 %. The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Active_site/1'>active site</scene> is the region with highest observed conservation, with a number of residues that are crucial in the mechanism of the enzyme (Lys210, Gln353, Glu357, Gln511, Lys518, His388b).
+'''Active Site''' - Mammalian PGI shows a degree of <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Conservation2/1'>conservation</scene> ( dark red for highly conserved regions - dark blue for variable reigions) of about 90 %. The <scene name='Stancu_Phosphoglucoisomerase_Sandbox_1/Active_site/1'>active site</scene> is the region with highest observed conservation, with a number of residues that are crucial in the mechanism of the enzyme (Lys210, Gln353, Glu357, Gln511, Lys518, His388b).
+[[Image:Active_site_movement.jpg|thumb|left|'''Figure 2.''' Substrate induced movement]]
+Another characteristic of phosphoglucose isomerase is that binding of substrate at the active site, induces a movement in the conformation of the enzyme. This can be seen in '''Figure 2''' as change in the position of an α helix.
-Another characteristic of phosphoglucose isomerase is that binding of substrate at the active site, induces a movement in the conformation of the enzyme. This can be seen in Figure 2 as change in the position of an α helix.
-[[Image:Active_site_movement.jpg|thumb|left|'''Figure 2.''' Substrate induced movement]]
 =='''Mechanism'''==
@@ Line 39: / Line 39: @@
-* Crystal Structure of human phosphoglucose isomerase (PDB=[[1iat]]<ref>PMID:11371164</ref>)
+* Crystal Structure of human phosphoglucose isomerase (PDB=[[1iat]])
 * Crystal Structure of rabbit phosphoglucose isomerase complexed fructose 6-phosphate (PDB=[[1hox]]<ref>PMID:11425306</ref>)