1pfk: Difference between revisions

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CRYSTAL STRUCTURE OF THE COMPLEX OF PHOSPHOFRUCTOKINASE FROM ESCHERICHIA COLI WITH ITS REACTION PRODUCTS

OverviewOverview

The crystal structure of Escherichia coli phosphofructokinase complexed with its reaction products fructose 1,6-bisphosphate (Fru1,6P) and ADP/Mg2+, and the allosteric activator ADP/Mg2+, has been determined at 2.4 A resolution. The structure was solved by molecular replacement using the known structure of Bacillus stearothermophilus phosphofructokinase, and has been refined to a crystallographic R-factor of 0.165 for all data. The crystallization mixture contained the substrate fructose 6-phosphate, but the electron density maps showed clearly the presence of the product fructose 1,6-bisphosphate, presumably formed by the enzyme reaction with contaminating ATP. The crystal consists of tetrameric molecules with subunits in two different conformations despite their chemical identity. The magnesium ion in the "closed" subunit bridges the phosphate groups of the two products. In the "open" subunit, the products are about 1.5 A further apart, with the Mg2+ bound only to ADP. These two conformations probably represent two successive stages along the reaction pathway, in which the closure of the subunit is required to bring the substrates sufficiently close to react. This conformational change within the subunit is distinct from the quaternary structure change seen previously in the inactive T-state conformation. It is probably not involved in the co-operativity or allosteric control of the enzyme, since the co-operative product fructose 1,6-bisphosphate is not moved, nor are the subunit interfaces changed. The structure of the enzyme is similar to that of B. stearothermophilus phosphofructokinase, and confirms the location of the sites for the two reaction products (or substrates), and of the effector site binding the activator ADP/Mg2+. However, this structure gives a clearer picture of the active site, and of the interactions between the enzyme and its reaction products.

About this StructureAbout this Structure

1PFK is a Single protein structure of sequence from Escherichia coli with , and as ligands. Active as 6-phosphofructokinase, with EC number 2.7.1.11 Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of the complex of phosphofructokinase from Escherichia coli with its reaction products., Shirakihara Y, Evans PR, J Mol Biol. 1988 Dec 20;204(4):973-94. PMID:2975709

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-[[Image:1pfk.gif|left|200px]]<br /><applet load="1pfk" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1pfk.gif|left|200px]]<br /><applet load="1pfk" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1pfk, resolution 2.4&Aring;" />
 '''CRYSTAL STRUCTURE OF THE COMPLEX OF PHOSPHOFRUCTOKINASE FROM ESCHERICHIA COLI WITH ITS REACTION PRODUCTS'''<br />
 ==Overview==
-The crystal structure of Escherichia coli phosphofructokinase complexed, with its reaction products fructose 1,6-bisphosphate (Fru1,6P) and, ADP/Mg2+, and the allosteric activator ADP/Mg2+, has been determined at, 2.4 A resolution. The structure was solved by molecular replacement using, the known structure of Bacillus stearothermophilus phosphofructokinase, and has been refined to a crystallographic R-factor of 0.165 for all data., The crystallization mixture contained the substrate fructose 6-phosphate, but the electron density maps showed clearly the presence of the product, fructose 1,6-bisphosphate, presumably formed by the enzyme reaction with, contaminating ATP. The crystal consists of tetrameric molecules with, subunits in two different conformations despite their chemical identity., The magnesium ion in the "closed" subunit bridges the phosphate groups of, the two products. In the "open" subunit, the products are about 1.5 A, further apart, with the Mg2+ bound only to ADP. These two conformations, probably represent two successive stages along the reaction pathway, in, which the closure of the subunit is required to bring the substrates, sufficiently close to react. This conformational change within the subunit, is distinct from the quaternary structure change seen previously in the, inactive T-state conformation. It is probably not involved in the, co-operativity or allosteric control of the enzyme, since the co-operative, product fructose 1,6-bisphosphate is not moved, nor are the subunit, interfaces changed. The structure of the enzyme is similar to that of B., stearothermophilus phosphofructokinase, and confirms the location of the, sites for the two reaction products (or substrates), and of the effector, site binding the activator ADP/Mg2+. However, this structure gives a, clearer picture of the active site, and of the interactions between the, enzyme and its reaction products.
+The crystal structure of Escherichia coli phosphofructokinase complexed with its reaction products fructose 1,6-bisphosphate (Fru1,6P) and ADP/Mg2+, and the allosteric activator ADP/Mg2+, has been determined at 2.4 A resolution. The structure was solved by molecular replacement using the known structure of Bacillus stearothermophilus phosphofructokinase, and has been refined to a crystallographic R-factor of 0.165 for all data. The crystallization mixture contained the substrate fructose 6-phosphate, but the electron density maps showed clearly the presence of the product fructose 1,6-bisphosphate, presumably formed by the enzyme reaction with contaminating ATP. The crystal consists of tetrameric molecules with subunits in two different conformations despite their chemical identity. The magnesium ion in the "closed" subunit bridges the phosphate groups of the two products. In the "open" subunit, the products are about 1.5 A further apart, with the Mg2+ bound only to ADP. These two conformations probably represent two successive stages along the reaction pathway, in which the closure of the subunit is required to bring the substrates sufficiently close to react. This conformational change within the subunit is distinct from the quaternary structure change seen previously in the inactive T-state conformation. It is probably not involved in the co-operativity or allosteric control of the enzyme, since the co-operative product fructose 1,6-bisphosphate is not moved, nor are the subunit interfaces changed. The structure of the enzyme is similar to that of B. stearothermophilus phosphofructokinase, and confirms the location of the sites for the two reaction products (or substrates), and of the effector site binding the activator ADP/Mg2+. However, this structure gives a clearer picture of the active site, and of the interactions between the enzyme and its reaction products.
 ==About this Structure==
-PFK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with FBP, MG and ADP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/6-phosphofructokinase 6-phosphofructokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.11 2.7.1.11] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1PFK OCA].
+PFK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=FBP:'>FBP</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=ADP:'>ADP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/6-phosphofructokinase 6-phosphofructokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.11 2.7.1.11] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PFK OCA].
 ==Reference==
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 [[Category: Escherichia coli]]
 [[Category: Single protein]]
-[[Category: Evans, P.R.]]
+[[Category: Evans, P R.]]
 [[Category: Shirakihara, Y.]]
 [[Category: ADP]]
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 [[Category: transferase(phosphotransferase)]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 23:45:44 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:28:14 2008''