3UT0

Crystal structure of exo-1,3/1,4-beta-glucanase (EXOP) from Pseudoalteromonas sp. BB1

「3F93」から置き換えられました

3UT0 の概要

• エントリーDOI: 10.2210/pdb3ut0/pdb
• 関連するPDBエントリー: 3F95 3RRX 3USZ
• 分子名称: Exo-1,3/1,4-beta-glucanase, CALCIUM ION, SODIUM ION, ... (6 entities in total)
• 機能のキーワード: (alpha/beta)8 barrel, (alpha/beta)6 sheet, beta-sandwich, hydrolase
• 由来する生物種: Pseudoalteromonas sp.
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 365026.30

構造登録者

Nakatani, Y.,Cutfield, S.M.,Cutfield, J.F. (登録日: 2011-11-24, 公開日: 2011-12-21, 最終更新日: 2024-11-13)

主引用文献

Nakatani, Y.,Cutfield, S.M.,Cowieson, N.P.,Cutfield, J.F.
Structure and activity of exo-1,3/1,4-beta-glucanase from marine bacterium Pseudoalteromonas sp. BB1 showing a novel C-terminal domain
Febs J., 2011

PubMed Abstract: Following the discovery of an exo-1,3/1,4-β-glucanase (glycoside hydrolase family 3) from a seaweed-associated bacterium Pseudoalteromonas sp. BB1, the recombinant three-domain protein (ExoP) was crystallized and its structure solved to 2.3 Å resolution. The first two domains of ExoP, both of which contribute to the architecture of the active site, are similar to those of the two-domain barley homologue β-d-glucan exohydrolase (ExoI) with a distinctive Trp-Trp clamp at the +1 subsite, although ExoI displays broader specificity towards β-glycosidic linkages. Notably, excision of the third domain of ExoP results in an inactive enzyme. Domain 3 has a β-sandwich structure and was shown by CD to be more temperature stable than the native enzyme. It makes relatively few contacts to domain 1 and none at all to domain 2. Two of the domain 3 residues involved at the interface, Q683 (forming one hydrogen bond) and Q676 (forming two hydrogen bonds) were mutated to alanine. Variant Q676A retained about half the activity of native ExoP, but the Q683A variant was severely attenuated. The crystal structure of Q683A-ExoP indicated that domain 3 was highly mobile and that Q683 is critical to the stabilization of ExoP by domain 3. Small-angle X-ray scattering data lent support to this proposal. Domain 3 does not appear to be an obvious carbohydrate-binding domain and is related neither in sequence nor structure to the additional domains characterized in other glycoside hydrolase 3 subgroups. Its major role appears to be for protein stability but it may also help orient substrate.

PubMed: 22129429
DOI: 10.1111/j.1742-4658.2011.08439.x

実験手法

X-RAY DIFFRACTION (2.3 Å)