1ohy

4-AMINOBUTYRATE-AMINOTRANSFERASE inactivated by gamma-ethynyl GABA

spinqualitylabelsall models 1ohy, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ohy is a 4 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.8Å Ligands: FES, GEG, PLP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GABT_PIG Catalyzes the conversion of gamma-aminobutyrate and L-beta-aminoisobutyrate to succinate semialdehyde and methylmalonate semialdehyde, respectively. Can also convert delta-aminovalerate and beta-alanine. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Gamma-aminobutyric acid aminotransferase (GABA-AT) is a pyridoxal 5'-phosphate-dependent enzyme responsible for the degradation of the inhibitory neurotransmitter GABA. GABA-AT is a validated target for antiepilepsy drugs because its selective inhibition raises GABA concentrations in brain. The antiepilepsy drug, gamma-vinyl-GABA (vigabatrin) has been investigated in the past by various biochemical methods and resulted in several proposals for its mechanisms of inactivation. In this study we solved and compared the crystal structures of pig liver GABA-AT in its native form (to 2.3-A resolution) and in complex with vigabatrin as well as with the close analogue gamma-ethynyl-GABA (to 2.3 and 2.8 A, respectively). Both inactivators form a covalent ternary adduct with the active site Lys-329 and the pyridoxal 5'-phosphate (PLP) cofactor. The crystal structures provide direct support for specific inactivation mechanisms proposed earlier on the basis of radio-labeling experiments. The reactivity of GABA-AT crystals with the two GABA analogues was also investigated by polarized absorption microspectrophotometry. The spectral data are discussed in relation to the proposed mechanism. Intriguingly, all three structures revealed a [2Fe-2S] cluster of yet unknown function at the center of the dimeric molecule in the vicinity of the PLP cofactors. Structures of gamma-aminobutyric acid (GABA) aminotransferase, a pyridoxal 5'-phosphate, and [2Fe-2S] cluster-containing enzyme, complexed with gamma-ethynyl-GABA and with the antiepilepsy drug vigabatrin.,Storici P, De Biase D, Bossa F, Bruno S, Mozzarelli A, Peneff C, Silverman RB, Schirmer T J Biol Chem. 2004 Jan 2;279(1):363-73. Epub 2003 Oct 8. PMID:14534310 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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