2PI8

Crystal structure of E. coli MltA with bound chitohexaose

2PI8 の概要

• エントリーDOI: 10.2210/pdb2pi8/pdb
• 関連するPDBエントリー: 2AE0 2PIC 2PJJ
• 分子名称: Membrane-bound lytic murein transglycosylase A, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, PHOSPHATE ION, ... (4 entities in total)
• 機能のキーワード: double-psi beta-barrel; protein-sugar complex; lytic transglycosylase, hydrolase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell outer membrane; Lipid-anchor: P0A935
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 160033.43

構造登録者

van Straaten, K.E.,Barends, T.R.M.,Dijkstra, B.W.,Thunnissen, A.M.W.H. (登録日: 2007-04-13, 公開日: 2007-05-08, 最終更新日: 2024-10-16)

主引用文献

van Straaten, K.E.,Barends, T.R.M.,Dijkstra, B.W.,Thunnissen, A.M.W.H.
Structure of Escherichia coli Lytic transglycosylase MltA with bound chitohexaose: implications for peptidoglycan binding and cleavage
J.Biol.Chem., 282:21197-21205, 2007

PubMed Abstract: Crystal structures of an inactive mutant (D308A) of the lytic transglycosylase MltA from Escherichia coli have been determined in two different apo-forms, as well as in complex with the substrate analogue chitohexaose. The chitohexaose binds with all six saccharide residues in the active site groove, with an intact glycosidic bond at the bond cleavage center. Its binding induces a large reorientation of the two structural domains in MltA, narrowing the active site groove and allowing tight interactions of the oligosaccharide with residues from both domains. The structures identify residues in MltA with key roles in the binding and recognition of peptidoglycan and confirm that Asp-308 is the single catalytic residue, acting as a general acid/base. Moreover, the structures suggest that catalysis involves a high energy conformation of the scissile glycosidic linkage and that the putative oxocarbenium ion intermediate is stabilized by the dipole moment of a nearby alpha-helix.

PubMed: 17502382
DOI: 10.1074/jbc.M701818200

実験手法

X-RAY DIFFRACTION (2.25 Å)