2qb2: Difference between revisions
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'''Structural Studies Reveal the Inactivation of E. coli L-aspartate aminotransferase by (s)-4,5-dihydro-2thiophenecarboylic acid (SADTA) via two mechanisms (at pH 7.0).''' | {{Structure | ||
|PDB= 2qb2 |SIZE=350|CAPTION= <scene name='initialview01'>2qb2</scene>, resolution 1.70Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=PSZ:4-[({3-HYDROXY-2-METHYL-5-[(PHOSPHONOOXY)METHYL]PYRIDIN-4-YL}METHYL)AMINO]THIOPHENE-2-CARBOXYLIC+ACID'>PSZ</scene>, <scene name='pdbligand=PMP:4'-DEOXY-4'-AMINOPYRIDOXAL-5'-PHOSPHATE'>PMP</scene> and <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Aspartate_transaminase Aspartate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.1 2.6.1.1] | |||
|GENE= aspC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Structural Studies Reveal the Inactivation of E. coli L-aspartate aminotransferase by (s)-4,5-dihydro-2thiophenecarboylic acid (SADTA) via two mechanisms (at pH 7.0).''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2QB2 is a [ | 2QB2 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QB2 OCA]. | ||
==Reference== | ==Reference== | ||
Inactivation of Escherichia coli L-aspartate aminotransferase by (S)-4-amino-4,5-dihydro-2-thiophenecarboxylic acid reveals "a tale of two mechanisms"., Liu D, Pozharski E, Lepore BW, Fu M, Silverman RB, Petsko GA, Ringe D, Biochemistry. 2007 Sep 18;46(37):10517-27. Epub 2007 Aug 22. PMID:[http:// | Inactivation of Escherichia coli L-aspartate aminotransferase by (S)-4-amino-4,5-dihydro-2-thiophenecarboxylic acid reveals "a tale of two mechanisms"., Liu D, Pozharski E, Lepore BW, Fu M, Silverman RB, Petsko GA, Ringe D, Biochemistry. 2007 Sep 18;46(37):10517-27. Epub 2007 Aug 22. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17713924 17713924] | ||
[[Category: Aspartate transaminase]] | [[Category: Aspartate transaminase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
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[[Category: sadta]] | [[Category: sadta]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 18:23:49 2008'' | ||
Revision as of 19:23, 20 March 2008
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| , resolution 1.70Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , and | ||||||
| Gene: | aspC (Escherichia coli) | ||||||
| Activity: | Aspartate transaminase, with EC number 2.6.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structural Studies Reveal the Inactivation of E. coli L-aspartate aminotransferase by (s)-4,5-dihydro-2thiophenecarboylic acid (SADTA) via two mechanisms (at pH 7.0).
OverviewOverview
As a mechanism-based inactivator of PLP-enzymes, (S)-4-amino-4,5-dihydro-2-thiophenecarboxylic acid (SADTA) was cocrystallized with Escherichia coli aspartate aminotransferase (l-AspAT) at a series of pH values ranging from 6 to 8. Five structural models with high resolution (1.4-1.85 A) were obtained for l-AspAT-SADTA complexes at pH 6.0, 6.5, 7.0, 7.5, and 8.0. Electron densities of the models showed that two different adducts had formed in the active sites. One adduct was formed from SADTA covalently linked to pyridoxal 5'-phosphate (PLP) while the other adduct was formed with the inhibitor covalently linked to Lysine246,1 the active site lysine. Moreover, there is a strong indication based on the electron densities that the occurrence of the two adducts is pH dependent. We conclude that SADTA inactivates l-AspAT via two different mechanisms based on the binding direction of the inactivator. Additionally, the structural models also show pH dependence of the protein structure itself, which provided detailed mechanistic implications for l-AspAT.
About this StructureAbout this Structure
2QB2 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Inactivation of Escherichia coli L-aspartate aminotransferase by (S)-4-amino-4,5-dihydro-2-thiophenecarboxylic acid reveals "a tale of two mechanisms"., Liu D, Pozharski E, Lepore BW, Fu M, Silverman RB, Petsko GA, Ringe D, Biochemistry. 2007 Sep 18;46(37):10517-27. Epub 2007 Aug 22. PMID:17713924
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