3C17
Hexagonal Crystal Structure of Precursor E. coli Isoaspartyl Peptidase/l-Asparaginase (ECAIII) with Active-site T179A mutation
Summary for 3C17
| Entry DOI | 10.2210/pdb3c17/pdb |
| Related | 1JN9 1K2X 1T3M 2GAC 2GEZ 2ZAK 2ZAL 9GAA 9GAC 9GAF |
| Descriptor | L-asparaginase precursor, SODIUM ION, CHLORIDE ION, ... (4 entities in total) |
| Functional Keywords | isoaspartyl peptidase, asparaginase, ntn-hydrolase, autoproteolysis, precursor, hydrolase |
| Biological source | Escherichia coli |
| Total number of polymer chains | 2 |
| Total formula weight | 67380.94 |
| Authors | Michalska, K.,Hernandez-Santoyo, A.,Jaskolski, M. (deposition date: 2008-01-22, release date: 2008-04-01, Last modification date: 2023-11-01) |
| Primary citation | Michalska, K.,Hernandez-Santoyo, A.,Jaskolski, M. The Mechanism of Autocatalytic Activation of Plant-type L-Asparaginases J.Biol.Chem., 283:13388-13397, 2008 Cited by PubMed Abstract: Plant l-asparaginases and their bacterial homologs, such as EcAIII found in Escherichia coli, form a subgroup of the N-terminal nucleophile (Ntn)-hydrolase family. In common with all Ntn-hydrolases, they are expressed as inactive precursors that undergo activation in an autocatalytic manner. The maturation process involves intramolecular hydrolysis of a single peptide bond, leading to the formation of two subunits (alpha and beta) folded as one structural domain, with the nucleophilic Thr residue located at the freed N terminus of subunit beta. The mechanism of the autocleavage reaction remains obscure. We have determined the crystal structure of an active site mutant of EcAIII, with the catalytic Thr residue substituted by Ala (T179A). The modification has led to a correctly folded but unprocessed molecule, revealing the geometry and molecular environment of the scissile peptide bond. The autocatalytic reaction is analyzed from the point of view of the Thr(179) side chain rotation, identification of a potential general base residue, and the architecture of the oxyanion hole. PubMed: 18334484DOI: 10.1074/jbc.M800746200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.95 Å) |
Structure validation
Download full validation report
