1szk: Difference between revisions
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|PDB= 1szk |SIZE=350|CAPTION= <scene name='initialview01'>1szk</scene>, resolution 2.52Å | |PDB= 1szk |SIZE=350|CAPTION= <scene name='initialview01'>1szk</scene>, resolution 2.52Å | ||
|SITE= | |SITE= | ||
|LIGAND= | |LIGAND= <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=PMP:4'-DEOXY-4'-AMINOPYRIDOXAL-5'-PHOSPHATE'>PMP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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] | |ACTIVITY= <span class='plainlinks'>[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] </span> | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1sf2|1SF2]], [[1sff|1SFF]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1szk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1szk OCA], [http://www.ebi.ac.uk/pdbsum/1szk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1szk RCSB]</span> | |||
}} | }} | ||
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[[Category: Peterson, P E.]] | [[Category: Peterson, P E.]] | ||
[[Category: Toney, M D.]] | [[Category: Toney, M D.]] | ||
[[Category: gaba-at]] | [[Category: gaba-at]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 23 | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:49:06 2008'' | ||
Revision as of 23:49, 30 March 2008
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| , resolution 2.52Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , | ||||||
| Activity: | 4-aminobutyrate transaminase, with EC number 2.6.1.19 | ||||||
| Related: | 1SF2, 1SFF
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
The structure of gamma-aminobutyrate aminotransferase mutant: E211S
OverviewOverview
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 StructureAbout this Structure
1SZK is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
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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