1ebb
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The crystal structure of Bacillus stearothermophilus PhoE (originally | + | The crystal structure of Bacillus stearothermophilus PhoE (originally termed YhfR), a broad specificity monomeric phosphatase with a molecular mass of approximately 24 kDa, has been solved at 2.3 A resolution in order to investigate its structure and function. PhoE, already identified as a homolog of a cofactor-dependent phosphoglycerate mutase, shares with the latter an alpha/beta/alpha sandwich structure spanning, as a structural excursion, a smaller subdomain composed of two alpha-helices and one short beta-strand. The active site contains residues from both the alpha/beta/alpha sandwich and the sub-domain. With the exception of the hydrophilic catalytic machinery conserved throughout the cofactor-dependent phosphoglycerate mutase family, the active-site cleft is strikingly hydrophobic. Docking studies with two diverse, favored substrates show that 3-phosphoglycerate may bind to the catalytic core, while alpha-napthylphosphate binding also involves the hydrophobic portion of the active-site cleft. Combining a highly favorable phospho group binding site common to these substrate binding modes and data from related enzymes, a catalytic mechanism can be proposed that involves formation of a phosphohistidine intermediate on His10 and likely acid-base behavior of Glu83. Other structural factors contributing to the broad substrate specificity of PhoE can be identified. The dynamic independence of the subdomain may enable the active-site cleft to accommodate substrates of different sizes, although similar motions are present in simulations of cofactor-dependent phosphoglycerate mutases, perhaps favoring a more general functional role. A significant number of entries in protein sequence databases, particularly from unfinished microbial genomes, are more similar to PhoE than to cofactor-dependent phosphoglycerate mutases or to fructose-2,6-bisphosphatases. This PhoE structure will therefore serve as a valuable basis for inference of structural and functional characteristics of these proteins. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Geobacillus stearothermophilus]] | [[Category: Geobacillus stearothermophilus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Jedrzejas, M | + | [[Category: Jedrzejas, M J.]] |
| - | [[Category: Rigden, D | + | [[Category: Rigden, D J.]] |
[[Category: GOL]] | [[Category: GOL]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: broad specificity phosphatase; dpgm homolog]] | [[Category: broad specificity phosphatase; dpgm homolog]] | ||
| - | ''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 12:25:56 2008'' |
Revision as of 10:25, 21 February 2008
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BACILLUS STEAROTHERMOPHILUS YHFR
Overview
The crystal structure of Bacillus stearothermophilus PhoE (originally termed YhfR), a broad specificity monomeric phosphatase with a molecular mass of approximately 24 kDa, has been solved at 2.3 A resolution in order to investigate its structure and function. PhoE, already identified as a homolog of a cofactor-dependent phosphoglycerate mutase, shares with the latter an alpha/beta/alpha sandwich structure spanning, as a structural excursion, a smaller subdomain composed of two alpha-helices and one short beta-strand. The active site contains residues from both the alpha/beta/alpha sandwich and the sub-domain. With the exception of the hydrophilic catalytic machinery conserved throughout the cofactor-dependent phosphoglycerate mutase family, the active-site cleft is strikingly hydrophobic. Docking studies with two diverse, favored substrates show that 3-phosphoglycerate may bind to the catalytic core, while alpha-napthylphosphate binding also involves the hydrophobic portion of the active-site cleft. Combining a highly favorable phospho group binding site common to these substrate binding modes and data from related enzymes, a catalytic mechanism can be proposed that involves formation of a phosphohistidine intermediate on His10 and likely acid-base behavior of Glu83. Other structural factors contributing to the broad substrate specificity of PhoE can be identified. The dynamic independence of the subdomain may enable the active-site cleft to accommodate substrates of different sizes, although similar motions are present in simulations of cofactor-dependent phosphoglycerate mutases, perhaps favoring a more general functional role. A significant number of entries in protein sequence databases, particularly from unfinished microbial genomes, are more similar to PhoE than to cofactor-dependent phosphoglycerate mutases or to fructose-2,6-bisphosphatases. This PhoE structure will therefore serve as a valuable basis for inference of structural and functional characteristics of these proteins.
About this Structure
1EBB is a Single protein structure of sequence from Geobacillus stearothermophilus with and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structure and mechanism of action of a cofactor-dependent phosphoglycerate mutase homolog from Bacillus stearothermophilus with broad specificity phosphatase activity., Rigden DJ, Mello LV, Setlow P, Jedrzejas MJ, J Mol Biol. 2002 Feb 1;315(5):1129-43. PMID:11827481
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