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3daa
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The three-dimensional structures of two forms of the D-amino acid, aminotransferase (D-aAT) from Bacillus sp. YM-1 have been determined, crystallographically: the pyridoxal phosphate (PLP) form and a complex, with the reduced analogue of the external aldimine, N-(5'-phosphopyridoxyl)-d-alanine (PPDA). Together with the previously, reported pyridoxamine phosphate form of the enzyme [Sugio et al. (1995), Biochemistry 34, 9661], these structures allow us to describe the pathway, of the enzymatic reaction in structural terms. A major determinant of the, enzyme's stereospecificity for D-amino acids is a group of three residues, (Tyr30, Arg98, and His100, with the latter two contributed by the, neighboring subunit) forming four hydrogen bonds to the substrate, alpha-carboxyl group. The . | + | The three-dimensional structures of two forms of the D-amino acid, aminotransferase (D-aAT) from Bacillus sp. YM-1 have been determined, crystallographically: the pyridoxal phosphate (PLP) form and a complex, with the reduced analogue of the external aldimine, N-(5'-phosphopyridoxyl)-d-alanine (PPDA). Together with the previously, reported pyridoxamine phosphate form of the enzyme [Sugio et al. (1995), Biochemistry 34, 9661], these structures allow us to describe the pathway, of the enzymatic reaction in structural terms. A major determinant of the, enzyme's stereospecificity for D-amino acids is a group of three residues, (Tyr30, Arg98, and His100, with the latter two contributed by the, neighboring subunit) forming four hydrogen bonds to the substrate, alpha-carboxyl group. The replacement by hydrophobic groups of the, homologous residues of the branched chain L-amino acid aminotransferase, (which has a similar fold) could explain its opposite stereospecificity., As in L-aspartate aminotransferase (L-AspAT), the cofactor in D-aAT tilts, (around its phosphate group and N1 as pivots) away from the catalytic, lysine 145 and the protein face in the course of the reaction. Unlike, L-AspAT, D-aAT shows no other significant conformational changes during, the reaction. |
==About this Structure== | ==About this Structure== | ||
| - | 3DAA is a | + | 3DAA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.] with PDD as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/D-amino-acid_transaminase D-amino-acid transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.21 2.6.1.21] Structure known Active Sites: ASA and ASB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=3DAA OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transaminase]] | [[Category: transaminase]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:58:08 2007'' |
Revision as of 12:52, 5 November 2007
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CRYSTALLOGRAPHIC STRUCTURE OF D-AMINO ACID AMINOTRANSFERASE INACTIVATED BY PYRIDOXYL-D-ALANINE
Overview
The three-dimensional structures of two forms of the D-amino acid, aminotransferase (D-aAT) from Bacillus sp. YM-1 have been determined, crystallographically: the pyridoxal phosphate (PLP) form and a complex, with the reduced analogue of the external aldimine, N-(5'-phosphopyridoxyl)-d-alanine (PPDA). Together with the previously, reported pyridoxamine phosphate form of the enzyme [Sugio et al. (1995), Biochemistry 34, 9661], these structures allow us to describe the pathway, of the enzymatic reaction in structural terms. A major determinant of the, enzyme's stereospecificity for D-amino acids is a group of three residues, (Tyr30, Arg98, and His100, with the latter two contributed by the, neighboring subunit) forming four hydrogen bonds to the substrate, alpha-carboxyl group. The replacement by hydrophobic groups of the, homologous residues of the branched chain L-amino acid aminotransferase, (which has a similar fold) could explain its opposite stereospecificity., As in L-aspartate aminotransferase (L-AspAT), the cofactor in D-aAT tilts, (around its phosphate group and N1 as pivots) away from the catalytic, lysine 145 and the protein face in the course of the reaction. Unlike, L-AspAT, D-aAT shows no other significant conformational changes during, the reaction.
About this Structure
3DAA is a Single protein structure of sequence from Bacillus sp. with PDD as ligand. Active as D-amino-acid transaminase, with EC number 2.6.1.21 Structure known Active Sites: ASA and ASB. Full crystallographic information is available from OCA.
Reference
Crystallographic study of steps along the reaction pathway of D-amino acid aminotransferase., Peisach D, Chipman DM, Van Ophem PW, Manning JM, Ringe D, Biochemistry. 1998 Apr 7;37(14):4958-67. PMID:9538014
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