3K8K

Crystal structure of SusG

3K8K の概要

• エントリーDOI: 10.2210/pdb3k8k/pdb
• 関連するPDBエントリー: 3K8L 3K8M
• 分子名称: Alpha-amylase, susG, MAGNESIUM ION, CALCIUM ION, ... (7 entities in total)
• 機能のキーワード: amylase, alpha8/beta8 barrel, cbm, beta-sandwich, membrane protein
• 由来する生物種: Bacteroides thetaiotaomicron
• 細胞内の位置: Cell outer membrane ; Lipid-anchor : Q8A1G3
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 152992.44

構造登録者

Koropatkin, N.M.,Smith, T.J. (登録日: 2009-10-14, 公開日: 2010-03-02, 最終更新日: 2024-11-27)

主引用文献

Koropatkin, N.M.,Smith, T.J.
SusG: A Unique Cell-Membrane-Associated alpha-Amylase from a Prominent Human Gut Symbiont Targets Complex Starch Molecules.
Structure, 18:200-215, 2010

PubMed Abstract: SusG is an alpha-amylase and part of a large protein complex on the outer surface of the bacterial cell and plays a major role in carbohydrate acquisition by the animal gut microbiota. Presented here, the atomic structure of SusG has an unusual extended, bilobed structure composed of amylase at one end and an unprecedented internal carbohydrate-binding motif at the other. Structural studies further demonstrate that the carbohydrate-binding motif binds maltooligosaccharide distal to, and on the opposite side of, the amylase catalytic site. SusG has an additional starch-binding site on the amylase domain immediately adjacent to the active cleft. Mutagenesis analysis demonstrates that these two additional starch-binding sites appear to play a role in catabolism of insoluble starch. However, elimination of these sites has only a limited effect, suggesting that they may have a more important role in product exchange with other Sus components.

PubMed: 20159465
DOI: 10.1016/j.str.2009.12.010

実験手法

X-RAY DIFFRACTION (2.2 Å)