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1szu

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[[Image:1szu.gif|left|200px]]<br /><applet load="1szu" size="350" color="white" frame="true" align="right" spinBox="true"
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[[Image:1szu.gif|left|200px]]
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caption="1szu, resolution 2.52&Aring;" />
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'''The structure of gamma-aminobutyrate aminotransferase mutant: V241A'''<br />
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{{Structure
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|PDB= 1szu |SIZE=350|CAPTION= <scene name='initialview01'>1szu</scene>, resolution 2.52&Aring;
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|SITE=
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|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>
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|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]
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|GENE= GABT, B2662 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])
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}}
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'''The structure of gamma-aminobutyrate aminotransferase mutant: V241A'''
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==Overview==
==Overview==
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==About this Structure==
==About this Structure==
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1SZU 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=SO4:'>SO4</scene>, <scene name='pdbligand=EDO:'>EDO</scene>, <scene name='pdbligand=PLP:'>PLP</scene> and <scene name='pdbligand=PMP:'>PMP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SZU OCA].
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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==
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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://ispc.weizmann.ac.il//pmbin/getpm?pmid=15723541 15723541]
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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]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:08:17 2008''
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''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

Image:1szu.gif


PDB ID 1szu

Drag the structure with the mouse to rotate
, resolution 2.52Å
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

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