Phosphoglycerate Mutase: Difference between revisions
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== Structure == | == Structure == | ||
In terms of the <scene name='Christopher_Vachon_Sandbox/Secondary_structures/1'>secondary structure</scene>, this protein is classified as an alpha/beta protein. Further, the fold is classified as “phosphoglycerate mutase-like”, having 3 main layers of alpha/beta/alpha. PGM contains a mixed beta sheet of 6 strands, with strand 5 existing as an anti-parallel strand to the rest. The quaternary structure usually is comprised of two identical subunits, thus this enzyme can be classified as a homodimer. The dimers have a relative molecular mass of 56,000-60,000 kDa. <ref name="winn">S., Winn I., Fothergill A. L., Harkins N. R., and Watson C. H. "Structure and Activity of Phosphoglycerate Mutase." Sciences 293.1063 (1981): 121-30. Print.</ref> | In terms of the <scene name='Christopher_Vachon_Sandbox/Secondary_structures/1'>secondary structure</scene>, this protein is classified as an alpha/beta protein. Further, the fold is classified as “phosphoglycerate mutase-like”, having 3 main layers of alpha/beta/alpha. PGM contains a mixed beta sheet of 6 strands, with strand 5 existing as an anti-parallel strand to the rest. The quaternary structure usually is comprised of two identical subunits, thus this enzyme can be classified as a homodimer. The dimers have a relative molecular mass of 56,000-60,000 kDa. <ref name="winn">S., Winn I., Fothergill A. L., Harkins N. R., and Watson C. H. "Structure and Activity of Phosphoglycerate Mutase." Sciences 293.1063 (1981): 121-30. Print.</ref> | ||
One exception includes the PGM enzyme of yeast which is a <scene name='Christopher_Vachon_Sandbox/Tetrameric/1'>homotetramer</scene> of mass 110,000 kDa. <ref name="winn" /> Though the quaternary structure is the same in terms of the active site, several variations exist, called isozymes, which depend on the tissue in which the enzyme is active. Mm-type, mb-type, and bb-type are isozymes that catalyze glycolysis in smooth muscle, cardiac and skeletal muscle, and the remaining tissues, respectively.<ref>"Phosphoglycerate mutase -." Wikipedia, the free encyclopedia. Web. 27 Feb. 2010. <http://en.wikipedia.org/wiki/Phosphoglycerate_mutase>.</ref> {{STRUCTURE_1qhf | PDB=1qhf | | One exception includes the PGM enzyme of yeast which is a <scene name='Christopher_Vachon_Sandbox/Tetrameric/1'>homotetramer</scene> of mass 110,000 kDa. <ref name="winn" /> Though the quaternary structure is the same in terms of the active site, several variations exist, called isozymes, which depend on the tissue in which the enzyme is active. Mm-type, mb-type, and bb-type are isozymes that catalyze glycolysis in smooth muscle, cardiac and skeletal muscle, and the remaining tissues, respectively.<ref>"Phosphoglycerate mutase -." Wikipedia, the free encyclopedia. Web. 27 Feb. 2010. <http://en.wikipedia.org/wiki/Phosphoglycerate_mutase>.</ref> | ||
{{STRUCTURE_1qhf| PDB=1qhf | SIZE=400| SCENE= |right|CAPTION=Yeast phosphoglycerate mutase complex with phosphoglyceric acid and sulfate, [[1qhf]] }} | |||
== Reaction and Mechanism == | == Reaction and Mechanism == | ||
PGM is an integral step in the process of glycolysis. Since this enzyme is a mutase, it will catalyze the transfer of a functional group from one position to another on a given substrate makin this an isomerization reaction. It is responsible for the conversion of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG), having 2,3-bisphosphoglycerate as an intermediate. <ref name="voet">Voet, Donald, Judith G. Voet, and Charlotte W. Pratt. Fundamentals of Biochemistry Life at the Molecular Level. New York: John Wiley & Sons, 2008. Print.</ref> With a Gibbs free energy of about 1.1 KJ/mol, this reaction is nearly energetically neutral. Despite this, it is absolutely necessary in order to generate the proper molecule needed to continue in the glycolytic pathway. The reaction that PGM catalyzes is shown below: | PGM is an integral step in the process of glycolysis. Since this enzyme is a mutase, it will catalyze the transfer of a functional group from one position to another on a given substrate makin this an isomerization reaction. It is responsible for the conversion of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG), having 2,3-bisphosphoglycerate as an intermediate. <ref name="voet">Voet, Donald, Judith G. Voet, and Charlotte W. Pratt. Fundamentals of Biochemistry Life at the Molecular Level. New York: John Wiley & Sons, 2008. Print.</ref> With a Gibbs free energy of about 1.1 KJ/mol, this reaction is nearly energetically neutral. Despite this, it is absolutely necessary in order to generate the proper molecule needed to continue in the glycolytic pathway. The reaction that PGM catalyzes is shown below: | ||