2e6c
From Proteopedia
(New page: 200px<br /><applet load="2e6c" size="350" color="white" frame="true" align="right" spinBox="true" caption="2e6c, resolution 2.05Å" /> '''Crystal structure of...) |
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==Overview== | ==Overview== | ||
| - | The stationary phase survival protein SurE is a metal ion-dependent | + | The stationary phase survival protein SurE is a metal ion-dependent phosphatase distributed among eubacteria, archaea, and eukaryotes. In Escherichia coli, SurE has activities as nucleotidase and exopolyphosphatase, and is thought to be involved in stress response. However, its physiological role and reaction mechanism are unclear. We report here the crystal structures of the tetramer of SurE from Thermus thermophilus HB8 (TtSurE) both alone and crystallized with Mn(2+) and substrate AMP. In the presence of Mn(2+) and AMP, differences between the protomers were observed in the active site and in the loop located near the active site; AMP-bound active sites with the loops in a novel open conformation were found in the two protomers, and AMP-free active sites with the loops in a conventional closed conformation were found in the other two protomers. The two loops in the open conformation are entwined with each other, and this entwining is suggested to be required for enzymatic activity by site-directed mutagenesis. TtSurE exists as an equilibrium mixture of dimer and tetramer in solution. The loop-entwined structure indicates that SurE acts as a tetramer. The structural features and the absence of negative cooperativity imply the half-of-the-sites reactivity mechanism resulting from a pre-existing tendency toward structural asymmetry. |
==About this Structure== | ==About this Structure== | ||
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[[Category: sure protein]] | [[Category: sure protein]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:06:36 2008'' |
Revision as of 15:06, 21 February 2008
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Crystal structure of the stationary phase survival protein SurE from Thermus thermophilus HB8 cocrystallized with manganese and AMP
Overview
The stationary phase survival protein SurE is a metal ion-dependent phosphatase distributed among eubacteria, archaea, and eukaryotes. In Escherichia coli, SurE has activities as nucleotidase and exopolyphosphatase, and is thought to be involved in stress response. However, its physiological role and reaction mechanism are unclear. We report here the crystal structures of the tetramer of SurE from Thermus thermophilus HB8 (TtSurE) both alone and crystallized with Mn(2+) and substrate AMP. In the presence of Mn(2+) and AMP, differences between the protomers were observed in the active site and in the loop located near the active site; AMP-bound active sites with the loops in a novel open conformation were found in the two protomers, and AMP-free active sites with the loops in a conventional closed conformation were found in the other two protomers. The two loops in the open conformation are entwined with each other, and this entwining is suggested to be required for enzymatic activity by site-directed mutagenesis. TtSurE exists as an equilibrium mixture of dimer and tetramer in solution. The loop-entwined structure indicates that SurE acts as a tetramer. The structural features and the absence of negative cooperativity imply the half-of-the-sites reactivity mechanism resulting from a pre-existing tendency toward structural asymmetry.
About this Structure
2E6C is a Single protein structure of sequence from Thermus thermophilus with , and as ligands. Active as 5'-nucleotidase, with EC number 3.1.3.5 Full crystallographic information is available from OCA.
Reference
Crystal structure of the stationary phase survival protein SurE with metal ion and AMP., Iwasaki W, Miki K, J Mol Biol. 2007 Aug 3;371(1):123-36. Epub 2007 May 10. PMID:17561111
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