3E74
Crystal structure of E. coli allantoinase with iron ions at the metal center
Summary for 3E74
| Entry DOI | 10.2210/pdb3e74/pdb |
| Related | 3E75 |
| Descriptor | Allantoinase, FE (III) ION (3 entities in total) |
| Functional Keywords | (beta/alpha)8-barrel domain, small beta-sheet domain, hydrolase, metal-binding, purine metabolism, zinc |
| Biological source | Escherichia coli |
| Total number of polymer chains | 4 |
| Total formula weight | 210856.85 |
| Authors | |
| Primary citation | Kim, K.,Kim, M.I.,Chung, J.,Ahn, J.H.,Rhee, S. Crystal structure of metal-dependent allantoinase from Escherichia coli J.Mol.Biol., 387:1067-1074, 2009 Cited by PubMed Abstract: Allantoinase acts as a key enzyme for the biogenesis and degradation of ureides by catalyzing the conversion of (S)-allantoin into allantoate, the final step in the ureide pathway. Despite limited sequence similarity, biochemical studies of the enzyme suggested that allantoinase belongs to the amidohydrolase family. In this study, the crystal structure of allantoinase from Escherichia coli was determined at 2.1 A resolution. The enzyme consists of a homotetramer in which each monomer contains two domains: a pseudo-triosephosphate-isomerase barrel and a beta-sheet. Analogous to other enzymes in the amidohydrolase family, allantoinase retains a binuclear metal center in the active site, embedded within the barrel fold. Structural analyses demonstrated that the metal ions in the active site ligate one hydroxide and six residues that are conserved among allantoinases from other organisms. Functional analyses showed that the presence of zinc in the metal center is essential for catalysis and enantioselectivity of substrate. Both the metal center and active site residues Asn94 and Ser317 play crucial roles in dictating enzyme activity. These structural and functional features are distinctively different from those of the metal-independent allantoinase, which was very recently identified. PubMed: 19248789DOI: 10.1016/j.jmb.2009.02.041 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
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