1szu
From Proteopedia
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- | [[Image:1szu.gif|left|200px]] | + | [[Image:1szu.gif|left|200px]] |
- | + | ||
- | '''The structure of gamma-aminobutyrate aminotransferase mutant: V241A''' | + | {{Structure |
+ | |PDB= 1szu |SIZE=350|CAPTION= <scene name='initialview01'>1szu</scene>, resolution 2.52Å | ||
+ | |SITE= | ||
+ | |LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5'-PHOSPHATE'>PLP</scene> and <scene name='pdbligand=PMP:4'-DEOXY-4'-AMINOPYRIDOXAL-5'-PHOSPHATE'>PMP</scene> | ||
+ | |ACTIVITY= [http://en.wikipedia.org/wiki/4-aminobutyrate_transaminase 4-aminobutyrate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.19 2.6.1.19] | ||
+ | |GENE= GABT, B2662 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
+ | }} | ||
+ | |||
+ | '''The structure of gamma-aminobutyrate aminotransferase mutant: V241A''' | ||
+ | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
- | 1SZU is a [ | + | 1SZU 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=1SZU OCA]. |
==Reference== | ==Reference== | ||
- | Kinetic and crystallographic analysis of active site mutants of Escherichia coli gamma-aminobutyrate aminotransferase., Liu W, Peterson PE, Langston JA, Jin X, Zhou X, Fisher AJ, Toney MD, Biochemistry. 2005 Mar 1;44(8):2982-92. PMID:[http:// | + | Kinetic and crystallographic analysis of active site mutants of Escherichia coli gamma-aminobutyrate aminotransferase., Liu W, Peterson PE, Langston JA, Jin X, Zhou X, Fisher AJ, Toney MD, Biochemistry. 2005 Mar 1;44(8):2982-92. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15723541 15723541] |
[[Category: 4-aminobutyrate transaminase]] | [[Category: 4-aminobutyrate transaminase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
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[[Category: gaba-at]] | [[Category: gaba-at]] | ||
- | ''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 14:11:45 2008'' |
Revision as of 12:11, 20 March 2008
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, resolution 2.52Å | |||||||
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Ligands: | , , and | ||||||
Gene: | GABT, B2662 (Escherichia coli) | ||||||
Activity: | 4-aminobutyrate transaminase, with EC number 2.6.1.19 | ||||||
Coordinates: | save as pdb, mmCIF, xml |
The structure of gamma-aminobutyrate aminotransferase mutant: V241A
Overview
The E. coli isozyme of gamma-aminobutyrate aminotransferase (GABA-AT) is a tetrameric pyridoxal phosphate-dependent enzyme that catalyzes transamination between primary amines and alpha-keto acids. The roles of the active site residues V241, E211, and I50 in the GABA-AT mechanism have been probed by site-directed mutagenesis. The beta-branched side chain of V241 facilitates formation of external aldimine intermediates with primary amine substrates, while E211 provides charge compensation of R398 selectively in the primary amine half-reaction and I50 forms a hydrophobic lid at the top of the substrate binding site. The structures of the I50Q, V241A, and E211S mutants were solved by X-ray crystallography to resolutions of 2.1, 2.5, and 2.52 A, respectively. The structure of GABA-AT is similar in overall fold and active site structure to that of dialkylglycine decarboxylase, which catalyzes both transamination and decarboxylation half-reactions in its normal catalytic cycle. Therefore, an attempt was made to convert GABA-AT into a decarboxylation-dependent aminotransferase similar to dialkylglycine decarboxylase by systematic mutation of E. coli GABA-AT active site residues. Two of the twelve mutants presented, E211S/I50G/C77K and E211S/I50H/V80D, have approximately 10-fold higher decarboxylation activities than the wild-type enzyme, and the E211S/I50H/V80D has formally changed the reaction specificity to that of a decarboxylase.
About this Structure
1SZU is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Kinetic and crystallographic analysis of active site mutants of Escherichia coli gamma-aminobutyrate aminotransferase., Liu W, Peterson PE, Langston JA, Jin X, Zhou X, Fisher AJ, Toney MD, Biochemistry. 2005 Mar 1;44(8):2982-92. PMID:15723541
Page seeded by OCA on Thu Mar 20 14:11:45 2008
Categories: 4-aminobutyrate transaminase | Escherichia coli | Single protein | Fisher, A J. | Jin, X. | Langston, J A. | Liu, W. | Peterson, P E. | Toney, M D. | Zhou, X. | EDO | PLP | PMP | SO4 | Gaba-at