Enolase: Difference between revisions

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Cory Tiedeman, David Canner, Michal Harel, Alexander Berchansky, Jaime Prilusky, Joel L. Sussman

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-[[Image:1one.png|left|200px|thumb|Crystal Structure of Enolase, [[1one]]]]
+<StructureSection load='1one' size='350' side='right' caption='Yeast enolase dimer complex with phosphoenolpyruvate and phosphoglycerate, [[1one]]' scene='Enolase/Enolase/1'><scene name='Cory_Tiedeman_Sandbox_1/Enolase/1'>Enolase</scene> is an enzyme that catalyzes a reaction of glycolysis. [[Glycolysis]] converts glucose into two 3-carbon molecules called pyruvate.  The energy released during glycolysis is used to make ATP.<ref>{{textbook |author=Voet, Donald; Voet, Judith C.; Pratt, Charlotte W.|title=Fundamentals of Biochemistry: Life at the Molecular Level|edition= 3|pages=487|}}</ref>  Enolase is used to convert 2-phosphoglycerate (2PG) to phosphoenolpyruvate (PEP) in the 9th reaction of glycolysis: it is a reversible dehydration reaction.<ref>{{textbook |author=Voet, Donald; Voet, Judith C.; Pratt, Charlotte W.|title=Fundamentals of Biochemistry: Life at the Molecular Level|edition= 3|pages=500|}}</ref>.  Enolase is expressed abundantly in most cells and has been proven useful as a model to study mechanisms of enzyme action and structural analysis <ref>{{journal}}</ref>. As with the reaction below, Enolase must have a divalent metal cation present to activate or deactivate the enzyme. The best cofactor would be Mg2+, but many, including Zn2+, Mn2+ and Co2+ can be used. The metal ion works by binding to the enzyme at the active site and producing a conformational change. This makes it possible for the substrate (2-PGA) to bind at the Enolase active site. Once this happens, a second metal ion comes in and binds to the enzyme to activate the enolase catalytic ability.  See [[Glycolysis Enzymes]].  For sequence alignment see [[Enolase multiple sequence alignment]].
-{{STRUCTURE_1one|  PDB=1one  | SIZE=400| SCENE=Enolase/Enolase/1 |right|CAPTION=Yeast enolase complex with phosphoenolpyruvate and phosphoglycerate, [[1one]] }}
+*'''Enolase 2''' or '''gamma enolase''' is found in neurons.
+*'''2,3-diketo-5-methylthiopentyl-1-phosphate enolase''' is part of the Met salvage pathway.
-<scene name='Cory_Tiedeman_Sandbox_1/Enolase/1'>Enolase</scene> is an enzyme that catalyzes a reaction of glycolysis.  Glycolysis converts glucose into two 3-carbon molecules called pyruvate.  The energy released during glycolysis is used to make ATP.<ref>{{textbook |author=Voet, Donald; Voet, Judith C.; Pratt, Charlotte W.|title=Fundamentals of Biochemistry: Life at the Molecular Level|edition= 3|pages=487|}}</ref>  Enolase is used to convert 2-phosphoglycerate (2PG) to phosphoenolpyruvate (PEP) in the 9th reaction of glycolysis: it is a reversible dehydration reaction.<ref>{{textbook |author=Voet, Donald; Voet, Judith C.; Pratt, Charlotte W.|title=Fundamentals of Biochemistry: Life at the Molecular Level|edition= 3|pages=500|}}</ref>.  Enolase is expressed abundantly in most cells and has been proven useful as a model to study mechanisms of enzyme action and structural analysis <ref>{{journal}}</ref>. As with the reaction below, Enolase must have a divalent metal cation present to activate or deactivate the enzyme. The best cofactor would be Mg2+, but many, including Zn2+, Mn2+ and Co2+ can be used. The metal ion works by binding to the enzyme at the active site and producing a conformational change. This makes it possible for the substrate (2-PGA) to bind at the Enolase active site. Once this happens, a second metal ion comes in and binds to the enzyme to activate the Enolase catalytic ability.
 ==Structure==
 The <scene name='Cory_Tiedeman_Sandbox_1/Secondary_structure/1'>secondary structure</scene> of enolase contains both alpha helices and beta sheets.  The beta sheets are mainly parallel<ref>{{web site| title=SCOP: Protein: Enolase from Baker's yeast (Saccharomyces cerevisiae)|url=http://scop.mrc-lmb.cam.ac.uk/scop/data/scop.b.d.b.bc.b.b.html|}}</ref>.  As shown in the figure, enolase has about 36 alpha helices and 22 beta sheets (18 alpha helices and 11 beta sheets per domain).  Enolase consists of two domains.
 '''Structural Clasification of Proteins (SCOP)<ref>{{web site| title=SCOP: Protein: Enolase from Baker's yeast (Saccharomyces cerevisiae)|url=http://scop.mrc-lmb.cam.ac.uk/scop/data/scop.b.d.b.bc.b.b.html|}}</ref>'''
@@ Line 14: / Line 10: @@
 Enolase is in the alpha and beta proteins class and has a fold of TIM beta/alpha-barrel.  It comes from the Superfamily on Enolase C-terminal domain-like and is in the enolase family.
+==Mechanism==
-==Mechanism==
+The <scene name='Cory_Tiedeman_Sandbox_1/Active_site/1'>active site</scene> of enolase as shown, involves Lys 345, Lys 396, Glu 168, Glu 211, and His 159.  Enolase forms a complex with two
-[[Image:mechanism.png|left|400px|The mechanism of 2PG to PEP using enolase.]]<ref>{{website2}}</ref>
-The
-<scene name='Cory_Tiedeman_Sandbox_1/Active_site/1'>active site</scene> of enolase as shown, involves Lys 345, Lys 396, Glu 168, Glu 211, and His 159.  Enolase forms a complex with two
 <scene name='Cory_Tiedeman_Sandbox_1/Mg/3'>Mg 2+'s</scene> at its active site.
 The substrate, 2PG, binds to the two <scene name='Cory_Tiedeman_Sandbox_1/Mechanism/4'>Mg2+'s, Glu 211, and Lys 345</scene>.  The Mg 2+ then forms a bond at the deprotonated carboxylic acid on the 1'C to connect it with enolase.  It also is connects to Glu 211 and Lys 345.  Glu 211 makes a hydrogen bond with the alcohol group on the 3'C.  Lys 345 deprotonates the 2'C and then the 2'C forms an alkene with the 1'C which then moves the electrons forming the ketone onto the oxygen making it have a negative charge.  The other oxygen, which already has a negative charge, then moves its electron to form a ketone with the 1'C.  The electrons that made up the alkene between the 1'C adn 2'C then moves to form an alkene between the 2'C and 3'C.  This breaks the bond with the alcohol on the 3'C which deprotonates Glu 211 on enolase to form H2O.  Then the new molecule is released from enolase as PEP.  PEP then goes on through another step in glycolysis to create pyruvate.
@@ Line 25: / Line 19: @@
 ==Kinetics==
-[[Image:enolase kinetics.jpeg|left|150px|V vs. [PGA]; PGA is 2PG, the top curve has [Mg2+] of 10^-3 M and the bottom curve has [Mg2+] of 106-2 M]]<ref>{{journal2}}</ref>
+[[Image:enolase kinetics.jpeg|left|200px|V vs. [PGA]; PGA is 2PG, the top curve has [Mg2+] of 10^-3 M and the bottom curve has [Mg2+] of 106-2 M]]<ref>{{journal2}}</ref>
 Since Mg2+ is essential for binding the substrate, 2-PG, it is also needed at a specific quality in order to have a good rate, or velocity.  The graph shows the V vs. [PGA], in which PGA is 2-PG, with two different concentrations of Mg2+.  The upper curve, which also has greater Vmax, has an Mg2+ concentration of 10^-3 M while the lower curve, which has a lower Vmax, has an Mg2+ concentration of 10^-2 M<ref>{{journal2}}</ref>.  The Km is also larger the upper curve making the higher [Mg2+] more desirable.
 ==Regulation==
@@ Line 38: / Line 31: @@
 ==3D structures of enolase==
+[[Enolase 3D structures]]
-''Update June 2012''
+</StructureSection>
-===Enolase===
-[[3dip]], [[2qgy]] – ENO – unidentified<BR />
-[[1oep]] - TbENO – ''Trypanosoma brucei''<BR />
-[[2ptw]] – TbENO (mutant) <BR />
-[[2ptx]] - TbENO (mutant) + sulfate<BR />
-[[2pty]] - TbENO (mutant) + PEP<BR />
-[[2ptz]], [[2pu0]], [[2pu1]] - TbENO (mutant) + PAH<BR />
-[[2pa6]] – ENO – ''Methanocaldococcus jannaschii''<BR />
-[[1w6t]] – ENO – ''Streptococcus pneumoniae''<BR />
-[[1iyx]] – ENO – ''Enterococcus hirae''<BR />
-[[1pdy]], [[1pdz]] – ENO – European lobster<br />
-[[3qn3]] – ENO – ''Campylobacter jejuni''<br />
-[[3tqp]] – ENO – ''Coxiella burnetii''<br />
-[[3ugv]] – ENO – ''Alpha proteobacterium''
-===Enolase 1===
-[[3b97]], [[2psn]] – hENO1 - human<BR />
-[[3otr]] – ENO1 – ''Toxoplasma gondii''<BR />
-[[3qtp]] – ENO1 – ''Entamoeba histolytica''<br />
-[[1e9i]] - EcENO1 – ''Escherichia coli''<BR />
-[[2xgz]], [[2xh0]], [[2xh2]], [[2xh4]], [[2xh7]] – EcENO1 residues 2-437 (mutant) <BR />
-[[3uj2]] – ENO1 – ''Anaerostipes caccae''<br />
-[[3h8a]], [[2fym]] – EcENO1 + RNase E<BR />
-[[3enl]], [[4enl]] – yENO1 - yeast<BR />
-[[2al1]], [[2al2]], [[1ebh]] – yENO1 + Mg<BR />
-[[1p43]], [[1p48]] – yENO1 (mutant) <BR />
-[[1ebg]], [[1els]] - yENO1 + PAH<BR />
-[[1l8p]] - yENO1 (mutant) + PAH<BR />
-[[2one]], [[1one]] – yENO1 + PEP + phosphoglycerate<BR />
-[[5enl]], [[7enl]] - yENO1 + phosphoglycerate<BR />
-[[1nel]], [[6enl]] – yENO1 + inhibitor
-===Enolase 2===
-[[1te6]] – hENO2<BR />
-[[2akm]], [[2akz]] – hENO2 + inhibitor
-===Enolase 3===
-[[2xsx]] - hENO3
-===2, 3-diketo-5-methylthiopentyl-1-phosphate enolase===
-[[2zvi]] – DK-MTP-1-P ENO – ''Bacillus subtilis''<br />
-[[2oej]] - BkDK-MTP-1-P ENO + Pi – ''Geobacillus kaustophilus''<br />
-[[2oek]], [[2oel]] - BkDK-MTP-1-P ENO + ion<br />
-[[2oem]] - BkDK-MTP-1-P ENO + Mg + phosphate derivative
 ==Additional Resources==