1x9h
From Proteopedia
(New page: 200px<br /><applet load="1x9h" size="450" color="white" frame="true" align="right" spinBox="true" caption="1x9h, resolution 1.50Å" /> '''Crystal structure of...) |
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| - | [[Image:1x9h.jpg|left|200px]]<br /><applet load="1x9h" size=" | + | [[Image:1x9h.jpg|left|200px]]<br /><applet load="1x9h" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1x9h, resolution 1.50Å" /> | caption="1x9h, resolution 1.50Å" /> | ||
'''Crystal structure of phosphoglucose/phosphomannose isomerase from Pyrobaculum aerophilum in complex with fructose 6-phosphate'''<br /> | '''Crystal structure of phosphoglucose/phosphomannose isomerase from Pyrobaculum aerophilum in complex with fructose 6-phosphate'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of a dual-specificity phosphoglucose/phosphomannose | + | The crystal structure of a dual-specificity phosphoglucose/phosphomannose isomerase from the crenarchaeon Pyrobaculum aerophilum (PaPGI/PMI) has been determined in complex with glucose 6-phosphate at 1.16 A resolution and with fructose 6-phosphate at 1.5 A resolution. Subsequent modeling of mannose 6-phosphate (M6P) into the active site of the enzyme shows that the PMI activity of this enzyme may be due to the additional space imparted by a threonine. In PGIs from bacterial and eukaryotic sources, which cannot use M6P as a substrate, the equivalent residue is a glutamine. The increased space may permit rotation of the C2-C3 bond in M6P to facilitate abstraction of a proton from C2 by Glu203 and, after a further C2-C3 rotation of the resulting cis-enediolate, re-donation of a proton to C1 by the same residue. A proline residue (in place of a glycine in PGI) may also promote PMI activity by positioning the C1-O1 region of M6P. Thus, the PMI reaction in PaPGI/PMI probably uses a cis-enediol mechanism of catalysis, and this activity appears to arise from a subtle difference in the architecture of the enzyme, compared to bacterial and eukaryotic PGIs. |
==About this Structure== | ==About this Structure== | ||
| - | 1X9H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrobaculum_aerophilum Pyrobaculum aerophilum] with SO4, F6R and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1X9H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrobaculum_aerophilum Pyrobaculum aerophilum] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=F6R:'>F6R</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1X9H OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hansen, T]] | [[Category: Hansen, T]] | ||
[[Category: Schoenheit, P.]] | [[Category: Schoenheit, P.]] | ||
| - | [[Category: Swan, M | + | [[Category: Swan, M K.]] |
[[Category: F6R]] | [[Category: F6R]] | ||
[[Category: GOL]] | [[Category: GOL]] | ||
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[[Category: pgi superfamily]] | [[Category: pgi superfamily]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:52:28 2008'' |
Revision as of 13:52, 21 February 2008
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Crystal structure of phosphoglucose/phosphomannose isomerase from Pyrobaculum aerophilum in complex with fructose 6-phosphate
Overview
The crystal structure of a dual-specificity phosphoglucose/phosphomannose isomerase from the crenarchaeon Pyrobaculum aerophilum (PaPGI/PMI) has been determined in complex with glucose 6-phosphate at 1.16 A resolution and with fructose 6-phosphate at 1.5 A resolution. Subsequent modeling of mannose 6-phosphate (M6P) into the active site of the enzyme shows that the PMI activity of this enzyme may be due to the additional space imparted by a threonine. In PGIs from bacterial and eukaryotic sources, which cannot use M6P as a substrate, the equivalent residue is a glutamine. The increased space may permit rotation of the C2-C3 bond in M6P to facilitate abstraction of a proton from C2 by Glu203 and, after a further C2-C3 rotation of the resulting cis-enediolate, re-donation of a proton to C1 by the same residue. A proline residue (in place of a glycine in PGI) may also promote PMI activity by positioning the C1-O1 region of M6P. Thus, the PMI reaction in PaPGI/PMI probably uses a cis-enediol mechanism of catalysis, and this activity appears to arise from a subtle difference in the architecture of the enzyme, compared to bacterial and eukaryotic PGIs.
About this Structure
1X9H is a Single protein structure of sequence from Pyrobaculum aerophilum with , and as ligands. Full crystallographic information is available from OCA.
Reference
Structural basis for phosphomannose isomerase activity in phosphoglucose isomerase from Pyrobaculum aerophilum: a subtle difference between distantly related enzymes., Swan MK, Hansen T, Schonheit P, Davies C, Biochemistry. 2004 Nov 9;43(44):14088-95. PMID:15518558
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