3A3Q

Structure of N59D HEN EGG-WHITE LYSOZYME in complex with (GlcNAc)3

3A3Q の概要

• エントリーDOI: 10.2210/pdb3a3q/pdb
• 関連するPDBエントリー: 1lza 3A3R
• 関連するBIRD辞書のPRD_ID: PRD_900017
• 分子名称: Lysozyme C, 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 (3 entities in total)
• 機能のキーワード: alpha and beta, allergen, antimicrobial, bacteriolytic enzyme, disulfide bond, glycosidase, hydrolase
• 由来する生物種: Gallus gallus (chicken)
• 細胞内の位置: Secreted: P00698
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14959.74

構造登録者

Ose, T.,Kuroki, K.,Matsushima, M.,Maenaka, K.,Kumagai, I. (登録日: 2009-06-16, 公開日: 2009-11-03, 最終更新日: 2024-10-23)

主引用文献

Ose, T.,Kuroki, K.,Matsushima, M.,Maenaka, K.,Kumagai, I.
Importance of the hydrogen bonding network including Asp52 for catalysis, as revealed by Asn59 mutant hen egg-white lysozymes
J.Biochem., 146:651-657, 2009

PubMed Abstract: In the catalysis of sugar hydrolysis by hen egg-white lysozyme, Asp52 is thought to stabilize the reaction intermediate. This residue is involved in the well-ordered hydrogen bonding network including Asn46, Asp48, Ser50 and Asn59 on the anti-parallel beta-sheet, designated as a 'platform', on which the substrate sugar sits. To reveal the role of this hydrogen bonding network in the hydrolysis, we characterized Asn59 mutants by biochemical and crystallographic studies. Surprisingly, the introduction of only a methylene group by the Asn59Gln mutation markedly reduced the bacteriolytic activity and abolished the hydrolytic activity towards the synthetic substrate, PNP-(GlcNAc)(5). A similar result was also obtained with the Asn59Asp mutant. The crystal structure of the Asn59Asp mutant in complex with the substrate analogue revealed that, as in the wild-type, the (GlcNAc)(3) was bound in the A-B-C subsites. The reduced activity would be caused by subtle changes in the side-chain orientations as well as the electrostatic characteristics of Asp59, resulting in the rearrangement of the hydrogen bonding network of the platform. These results suggest that the precise locations of these 'platform' residues, maintained by the well-ordered hydrogen bonding network, are crucial for efficient hydrolysis.

PubMed: 19605465
DOI: 10.1093/jb/mvp110

実験手法

X-RAY DIFFRACTION (2 Å)