1els
From Proteopedia
(New page: 200px<br /><applet load="1els" size="450" color="white" frame="true" align="right" spinBox="true" caption="1els, resolution 2.4Å" /> '''CATALYTIC METAL ION B...) |
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| - | [[Image:1els.gif|left|200px]]<br /><applet load="1els" size=" | + | [[Image:1els.gif|left|200px]]<br /><applet load="1els" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1els, resolution 2.4Å" /> | caption="1els, resolution 2.4Å" /> | ||
'''CATALYTIC METAL ION BINDING IN ENOLASE: THE CRYSTAL STRUCTURE OF ENOLASE-MN2+-PHOSPHONOACETOHYDROXAMATE COMPLEX AT 2.4 ANGSTROMS RESOLUTION'''<br /> | '''CATALYTIC METAL ION BINDING IN ENOLASE: THE CRYSTAL STRUCTURE OF ENOLASE-MN2+-PHOSPHONOACETOHYDROXAMATE COMPLEX AT 2.4 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Enolase, a glycolytic enzyme that catalyzes the dehydration of | + | Enolase, a glycolytic enzyme that catalyzes the dehydration of 2-phospho-D-glycerate (PGA) to form phosphoenolpyruvate (PEP), requires two divalent metal ions per active site for activity. The first metal ion, traditionally referred to as "conformational", binds in a high-affinity site I. The second metal ion, "catalytic", binds in site II only in the presence of a substrate or substrate analogue and with much lower affinity for the physiological cofactor Mg2+. While the high-affinity site has been well characterized, the position of the lower affinity site has not been established so far. Here, we report the structure of the quaternary complex between enolase, the transition-state analogue phosphonoacetohydroxamate (PhAH), and two Mn2+ ions. The structure has been refined by using 16 561 reflections with F/sigma (F) > or = 3 to an R = 0.165 with average deviations of bond lengths and bond angles from ideal values of 0.013 A and 3.1 degrees, respectively. The "catalytic" metal ion is coordinated to two oxygen atoms of the phosphono moiety of PhAH and to the carbonyl oxygen of Gly37. Most likely, disordered water molecules complement its coordination sphere. The interaction with the site II metal ion must stabilize negative charge on the phosphate group and produce electron withdrawal from carbon 2 of the substrate, facilitating proton abstraction from carbon 2, the rate-limiting step in the catalytic process. The Gly37 residue is located in the flexible loop Ser36-His43, which assumes an "open" conformation in the absence of substrate and a "closed" conformation in the presence of a substrate.(ABSTRACT TRUNCATED AT 250 WORDS) |
==About this Structure== | ==About this Structure== | ||
| - | 1ELS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with MN and PAH as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphopyruvate_hydratase Phosphopyruvate hydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.11 4.2.1.11] Full crystallographic information is available from [http:// | + | 1ELS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=MN:'>MN</scene> and <scene name='pdbligand=PAH:'>PAH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphopyruvate_hydratase Phosphopyruvate hydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.11 4.2.1.11] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ELS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Saccharomyces cerevisiae]] | [[Category: Saccharomyces cerevisiae]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Brewer, J | + | [[Category: Brewer, J M.]] |
[[Category: Hatada, M.]] | [[Category: Hatada, M.]] | ||
[[Category: Lebioda, L.]] | [[Category: Lebioda, L.]] | ||
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[[Category: carbon-oxygen lyase]] | [[Category: carbon-oxygen lyase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:29:05 2008'' |
Revision as of 10:29, 21 February 2008
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CATALYTIC METAL ION BINDING IN ENOLASE: THE CRYSTAL STRUCTURE OF ENOLASE-MN2+-PHOSPHONOACETOHYDROXAMATE COMPLEX AT 2.4 ANGSTROMS RESOLUTION
Overview
Enolase, a glycolytic enzyme that catalyzes the dehydration of 2-phospho-D-glycerate (PGA) to form phosphoenolpyruvate (PEP), requires two divalent metal ions per active site for activity. The first metal ion, traditionally referred to as "conformational", binds in a high-affinity site I. The second metal ion, "catalytic", binds in site II only in the presence of a substrate or substrate analogue and with much lower affinity for the physiological cofactor Mg2+. While the high-affinity site has been well characterized, the position of the lower affinity site has not been established so far. Here, we report the structure of the quaternary complex between enolase, the transition-state analogue phosphonoacetohydroxamate (PhAH), and two Mn2+ ions. The structure has been refined by using 16 561 reflections with F/sigma (F) > or = 3 to an R = 0.165 with average deviations of bond lengths and bond angles from ideal values of 0.013 A and 3.1 degrees, respectively. The "catalytic" metal ion is coordinated to two oxygen atoms of the phosphono moiety of PhAH and to the carbonyl oxygen of Gly37. Most likely, disordered water molecules complement its coordination sphere. The interaction with the site II metal ion must stabilize negative charge on the phosphate group and produce electron withdrawal from carbon 2 of the substrate, facilitating proton abstraction from carbon 2, the rate-limiting step in the catalytic process. The Gly37 residue is located in the flexible loop Ser36-His43, which assumes an "open" conformation in the absence of substrate and a "closed" conformation in the presence of a substrate.(ABSTRACT TRUNCATED AT 250 WORDS)
About this Structure
1ELS is a Single protein structure of sequence from Saccharomyces cerevisiae with and as ligands. Active as Phosphopyruvate hydratase, with EC number 4.2.1.11 Full crystallographic information is available from OCA.
Reference
Catalytic metal ion binding in enolase: the crystal structure of an enolase-Mn2+-phosphonoacetohydroxamate complex at 2.4-A resolution., Zhang E, Hatada M, Brewer JM, Lebioda L, Biochemistry. 1994 May 24;33(20):6295-300. PMID:8193144
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