6B15

Crystal structure of CBMbc (family CBM26) from Eubacterium rectale Amy13K

6B15 の概要

• エントリーDOI: 10.2210/pdb6b15/pdb
• 関連するPDBエントリー: 6AZ5
• 分子名称: Amy13K, 1,2-ETHANEDIOL (3 entities in total)
• 機能のキーワード: carbohydrate binding module, amylase, starch, gut microbiome, eubacterium rectale, sugar binding protein
• 由来する生物種: Eubacterium rectale DSM 17629
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 92001.99

構造登録者

Cockburn, D.W.,Wawrzak, Z.,Perez Medina, K.,Koropatkin, N.M. (登録日: 2017-09-16, 公開日: 2017-11-29, 最終更新日: 2024-03-13)

主引用文献

Cockburn, D.W.,Suh, C.,Medina, K.P.,Duvall, R.M.,Wawrzak, Z.,Henrissat, B.,Koropatkin, N.M.
Novel carbohydrate binding modules in the surface anchored alpha-amylase of Eubacterium rectale provide a molecular rationale for the range of starches used by this organism in the human gut.
Mol. Microbiol., 107:249-264, 2018

PubMed Abstract: Gut bacteria recognize accessible glycan substrates within a complex environment. Carbohydrate binding modules (CBMs) of cell surface glycoside hydrolases often drive binding to the target substrate. Eubacterium rectale, an important butyrate-producing organism in the gut, consumes a limited range of substrates, including starch. Host consumption of resistant starch increases the abundance of E. rectale in the intestine, likely because it successfully captures the products of resistant starch degradation by other bacteria. Here, we demonstrate that the cell wall anchored starch-degrading α-amylase, Amy13K of E. rectale harbors five CBMs that all target starch with differing specificities. Intriguingly these CBMs efficiently bind to both regular and high amylose corn starch (a type of resistant starch), but have almost no affinity for potato starch (another type of resistant starch). Removal of these CBMs from Amy13K reduces the activity level of the enzyme toward corn starches by ∼40-fold, down to the level of activity toward potato starch, suggesting that the CBMs facilitate activity on corn starch and allow its utilization in vivo. The specificity of the Amy13K CBMs provides a molecular rationale for why E. rectale is able to only use certain starch types without the aid of other organisms.

PubMed: 29139580
DOI: 10.1111/mmi.13881

実験手法

X-RAY DIFFRACTION (2.1 Å)