1pmo
From Proteopedia
(New page: 200px<br /><applet load="1pmo" size="450" color="white" frame="true" align="right" spinBox="true" caption="1pmo, resolution 2.3Å" /> '''Crystal structure of ...) |
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| - | [[Image:1pmo.gif|left|200px]]<br /><applet load="1pmo" size=" | + | [[Image:1pmo.gif|left|200px]]<br /><applet load="1pmo" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1pmo, resolution 2.3Å" /> | caption="1pmo, resolution 2.3Å" /> | ||
'''Crystal structure of Escherichia coli GadB (neutral pH)'''<br /> | '''Crystal structure of Escherichia coli GadB (neutral pH)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Glutamate decarboxylase is a vitamin B6-dependent enzyme, which catalyses | + | Glutamate decarboxylase is a vitamin B6-dependent enzyme, which catalyses the decarboxylation of glutamate to gamma-aminobutyrate. In Escherichia coli, expression of glutamate decarboxylase (GadB), a 330 kDa hexamer, is induced to maintain the physiological pH under acidic conditions, like those of the passage through the stomach en route to the intestine. GadB, together with the antiporter GadC, constitutes the gad acid resistance system, which confers the ability for bacterial survival for at least 2 h in a strongly acidic environment. GadB undergoes a pH-dependent conformational change and exhibits an activity optimum at low pH. We determined the crystal structures of GadB at acidic and neutral pH. They reveal the molecular details of the conformational change and the structural basis for the acidic pH optimum. We demonstrate that the enzyme is localized exclusively in the cytoplasm at neutral pH, but is recruited to the membrane when the pH falls. We show by structure-based site-directed mutagenesis that the triple helix bundle formed by the N-termini of the protein at acidic pH is the major determinant for this behaviour. |
==About this Structure== | ==About this Structure== | ||
| - | 1PMO 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 PLR and TRS as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutamate_decarboxylase Glutamate decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.15 4.1.1.15] Full crystallographic information is available from [http:// | + | 1PMO 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=PLR:'>PLR</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutamate_decarboxylase Glutamate decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.15 4.1.1.15] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PMO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Aurizi, C.]] | [[Category: Aurizi, C.]] | ||
| - | [[Category: Biase, D | + | [[Category: Biase, D De.]] |
[[Category: Bossa, F.]] | [[Category: Bossa, F.]] | ||
[[Category: Capitani, G.]] | [[Category: Capitani, G.]] | ||
| - | [[Category: Grutter, M | + | [[Category: Grutter, M G.]] |
[[Category: Gut, H.]] | [[Category: Gut, H.]] | ||
[[Category: PLR]] | [[Category: PLR]] | ||
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[[Category: neutral-ph form of gadb]] | [[Category: neutral-ph form of gadb]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:30:21 2008'' |
Revision as of 12:30, 21 February 2008
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Crystal structure of Escherichia coli GadB (neutral pH)
Overview
Glutamate decarboxylase is a vitamin B6-dependent enzyme, which catalyses the decarboxylation of glutamate to gamma-aminobutyrate. In Escherichia coli, expression of glutamate decarboxylase (GadB), a 330 kDa hexamer, is induced to maintain the physiological pH under acidic conditions, like those of the passage through the stomach en route to the intestine. GadB, together with the antiporter GadC, constitutes the gad acid resistance system, which confers the ability for bacterial survival for at least 2 h in a strongly acidic environment. GadB undergoes a pH-dependent conformational change and exhibits an activity optimum at low pH. We determined the crystal structures of GadB at acidic and neutral pH. They reveal the molecular details of the conformational change and the structural basis for the acidic pH optimum. We demonstrate that the enzyme is localized exclusively in the cytoplasm at neutral pH, but is recruited to the membrane when the pH falls. We show by structure-based site-directed mutagenesis that the triple helix bundle formed by the N-termini of the protein at acidic pH is the major determinant for this behaviour.
About this Structure
1PMO is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Glutamate decarboxylase, with EC number 4.1.1.15 Full crystallographic information is available from OCA.
Reference
Crystal structure and functional analysis of Escherichia coli glutamate decarboxylase., Capitani G, De Biase D, Aurizi C, Gut H, Bossa F, Grutter MG, EMBO J. 2003 Aug 15;22(16):4027-37. PMID:12912902
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