1knp | pdb_00001knp
E. coli L-aspartate oxidase: mutant R386L in complex with succinate
Structural highlights
Function[NADB_ECOLI] Catalyzes the oxidation of L-aspartate to iminoaspartate. 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 PubMedL-Aspartate oxidase (Laspo) catalyzes the conversion of L-Asp to iminoaspartate, the first step in the de novo biosynthesis of NAD(+). This bacterial pathway represents a potential drug target since it is absent in mammals. The Laspo R386L mutant was crystallized in the FAD-bound catalytically competent form and its three-dimensional structure determined at 2.5 A resolution in both the native state and in complex with succinate. Comparison of the R386L holoprotein with the wild-type apoenzyme [Mattevi, A., Tedeschi, G., Bacchella, L., Coda, A., Negri, A., and Ronchi, S. (1999) Structure 7, 745-756] reveals that cofactor incorporation leads to the ordering of two polypeptide segments (residues 44-53 and 104-141) and to a 27 degree rotation of the capping domain. This motion results in the formation of the active site cavity, located at the interface between the capping domain and the FAD-binding domain. The structure of the succinate complex indicates that the cavity surface is decorated by two clusters of H-bond donors that anchor the ligand carboxylates. Moreover, Glu121, which is strictly conserved among Laspo sequences, is positioned to interact with the L-Asp alpha-amino group. The architecture of the active site of the Laspo holoenzyme is remarkably similar to that of respiratory fumarate reductases, providing strong evidence for a common mechanism of catalysis in Laspo and flavoproteins of the succinate dehydrogenase/fumarate reductase family. This implies that Laspo is mechanistically distinct from other flavin-dependent amino acid oxidases, such as the prototypical D-amino acid oxidase. Structure of FAD-bound L-aspartate oxidase: insight into substrate specificity and catalysis.,Bossi RT, Negri A, Tedeschi G, Mattevi A Biochemistry. 2002 Mar 5;41(9):3018-24. PMID:11863440[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References | ||||||||||||||||||||||||
