2dgl
From Proteopedia
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|PDB= 2dgl |SIZE=350|CAPTION= <scene name='initialview01'>2dgl</scene>, resolution 3.15Å | |PDB= 2dgl |SIZE=350|CAPTION= <scene name='initialview01'>2dgl</scene>, resolution 3.15Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5 | + | |LIGAND= <scene name='pdbligand=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5'-PHOSPHATE'>PLP</scene> and <scene name='pdbligand=ACY:ACETIC ACID'>ACY</scene> |
|ACTIVITY= [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] | |ACTIVITY= [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] | ||
|GENE= gadB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |GENE= gadB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
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[[Category: gadb complexed with bromide]] | [[Category: gadb complexed with bromide]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 23 14:56:25 2008'' |
Revision as of 12:56, 23 March 2008
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| , resolution 3.15Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , and | ||||||
| Gene: | gadB (Escherichia coli) | ||||||
| Activity: | Glutamate decarboxylase, with EC number 4.1.1.15 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of Escherichia coli GadB in complex with bromide
Overview
Escherichia coli and other enterobacteria exploit the H+ -consuming reaction catalysed by glutamate decarboxylase to survive the stomach acidity before reaching the intestine. Here we show that chloride, extremely abundant in gastric secretions, is an allosteric activator producing a 10-fold increase in the decarboxylase activity at pH 5.6. Cooperativity and sensitivity to chloride were lost when the N-terminal 14 residues, involved in the formation of two triple-helix bundles, were deleted by mutagenesis. X-ray structures, obtained in the presence of the substrate analogue acetate, identified halide-binding sites at the base of each N-terminal helix, showed how halide binding is responsible for bundle stability and demonstrated that the interconversion between active and inactive forms of the enzyme is a stepwise process. We also discovered an entirely novel structure of the cofactor pyridoxal 5'-phosphate (aldamine) to be responsible for the reversibly inactivated enzyme. Our results link the entry of chloride ions, via the H+/Cl- exchange activities of ClC-ec1, to the trigger of the acid stress response in the cell when the intracellular proton concentration has not yet reached fatal values.
About this Structure
2DGL is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Escherichia coli acid resistance: pH-sensing, activation by chloride and autoinhibition in GadB., Gut H, Pennacchietti E, John RA, Bossa F, Capitani G, De Biase D, Grutter MG, EMBO J. 2006 Jun 7;25(11):2643-51. Epub 2006 May 4. PMID:16675957
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