3C17

Hexagonal Crystal Structure of Precursor E. coli Isoaspartyl Peptidase/l-Asparaginase (ECAIII) with Active-site T179A mutation

3C17 の概要

• エントリーDOI: 10.2210/pdb3c17/pdb
• 関連するPDBエントリー: 1JN9 1K2X 1T3M 2GAC 2GEZ 2ZAK 2ZAL 9GAA 9GAC 9GAF
• 分子名称: L-asparaginase precursor, SODIUM ION, CHLORIDE ION, ... (4 entities in total)
• 機能のキーワード: isoaspartyl peptidase, asparaginase, ntn-hydrolase, autoproteolysis, precursor, hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 67380.94

構造登録者

Michalska, K.,Hernandez-Santoyo, A.,Jaskolski, M. (登録日: 2008-01-22, 公開日: 2008-04-01, 最終更新日: 2023-11-01)

主引用文献

Michalska, K.,Hernandez-Santoyo, A.,Jaskolski, M.
The Mechanism of Autocatalytic Activation of Plant-type L-Asparaginases
J.Biol.Chem., 283:13388-13397, 2008

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: 18334484
DOI: 10.1074/jbc.M800746200

実験手法

X-RAY DIFFRACTION (1.95 Å)