1rk5

The D-aminoacylase mutant D366A in complex with 100mM CuCl2The D-aminoacylase mutant D366A in complex with 100mM CuCl2

Structural highlights 1rk5 is a 1 chain structure with sequence from Alcaligenes faecalis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.8Å Ligands: , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q9AGH8_ALCFA 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 Our structural comparison of the TIM barrel metal-dependent hydrolase(-like) superfamily suggests a classification of their divergent active sites into four types: alphabeta-binuclear, alpha-mononuclear, beta-mononuclear, and metal-independent subsets. The d-aminoacylase from Alcaligenes faecalis DA1 belongs to the beta-mononuclear subset due to the fact that the catalytically essential Zn(2+) is tightly bound at the beta site with coordination by Cys(96), His(220), and His(250), even though it possesses a binuclear active site with a weak alpha binding site. Additional Zn(2+), Cd(2+), and Cu(2+), but not Ni(2+), Co(2+), Mg(2+), Mn(2+), and Ca(2+), can inhibit enzyme activity. Crystal structures of these metal derivatives show that Zn(2+) and Cd(2+) bind at the alpha(1) subsite ligated by His(67), His(69), and Asp(366), while Cu(2+) at the alpha(2) subsite is chelated by His(67), His(69) and Cys(96). Unexpectedly, the crystal structure of the inactive H220A mutant displays that the endogenous Zn(2+) shifts to the alpha(3) subsite coordinated by His(67), His(69), Cys(96), and Asp(366), revealing that elimination of the beta site changes the coordination geometry of the alpha ion with an enhanced affinity. Kinetic studies of the metal ligand mutants such as C96D indicate the uniqueness of the unusual bridging cysteine and its involvement in catalysis. Therefore, the two metal-binding sites in the d-aminoacylase are interactive with partially mutual exclusion, thus resulting in widely different affinities for the activation/attenuation mechanism, in which the enzyme is activated by the metal ion at the beta site, but inhibited by the subsequent binding of the second ion at the alpha site. The functional role of the binuclear metal center in D-aminoacylase: one-metal activation and second-metal attenuation.,Lai WL, Chou LY, Ting CY, Kirby R, Tsai YC, Wang AH, Liaw SH J Biol Chem. 2004 Apr 2;279(14):13962-7. Epub 2004 Jan 21. PMID:14736882 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacylase 3D structures

spinqualitylabelsall models 1rk5, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image