3daa

CRYSTALLOGRAPHIC STRUCTURE OF D-AMINO ACID AMINOTRANSFERASE INACTIVATED BY PYRIDOXYL-D-ALANINECRYSTALLOGRAPHIC STRUCTURE OF D-AMINO ACID AMINOTRANSFERASE INACTIVATED BY PYRIDOXYL-D-ALANINE

Structural highlights 3daa is a 2 chain structure with sequence from Bacym. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Activity: D-amino-acid transaminase, with EC number 2.6.1.21 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [DAAA_BACYM] Acts on the D-isomers of alanine, leucine, aspartate, glutamate, aminobutyrate, norvaline and asparagine. The enzyme transfers an amino group from a substrate D-amino acid to the pyridoxal phosphate cofactor to form pyridoxamine and an alpha-keto acid in the first half-reaction. The second-half reaction is the reverse of the first, transferring the amino group from the pyridoxamine to a second alpha-keto acid to form the product D-amino acid via a ping-pong mechanism. This is an important process in the formation of D-alanine and D-glutamate, which are essential bacterial cell wall components. 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 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminotransferase Aspartate Aminotransferase

spinqualitylabelsall models 3daa, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image