5JBD

4,6-alpha-glucanotransferase GTFB from Lactobacillus reuteri 121

5JBD の概要

• エントリーDOI: 10.2210/pdb5jbd/pdb
• 分子名称: Inactive glucansucrase, CALCIUM ION, ACETATE ION, ... (7 entities in total)
• 機能のキーワード: 4, 6-alpha-glucanotransferase, starch conversion, gh70, transferase
• 由来する生物種: Lactobacillus reuteri
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 200757.44

構造登録者

Pijning, T.,Dijkstra, B.W.,Bai, Y.,Gangoiti-Munecas, J.,Dijkhuizen, L. (登録日: 2016-04-13, 公開日: 2017-01-18, 最終更新日: 2024-01-10)

主引用文献

Bai, Y.,Gangoiti, J.,Dijkstra, B.W.,Dijkhuizen, L.,Pijning, T.
Crystal Structure of 4,6-alpha-Glucanotransferase Supports Diet-Driven Evolution of GH70 Enzymes from alpha-Amylases in Oral Bacteria.
Structure, 25:231-242, 2017

PubMed Abstract: Food processing and refining has dramatically changed the human diet, but little is known about whether this affected the evolution of enzymes in human microbiota. We present evidence that glycoside hydrolase family 70 (GH70) glucansucrases from lactobacilli, synthesizing α-glucan-type extracellular polysaccharides from sucrose, likely evolved from GH13 starch-acting α-amylases, via GH70 4,6-α-glucanotransferases. The crystal structure of a 4,6-α-glucanotransferase explains the mode of action and unique product specificity of these enzymes. While the α-amylase substrate-binding scaffold is retained, active-site loops adapted to favor transglycosylation over hydrolysis; the structure also gives clues as to how 4,6-α-glucanotransferases may have evolved further toward sucrose utilization instead of starch. Further supported by genomic, phylogenetic, and in vivo studies, we propose that dietary changes involving starch (and starch derivatives) and sucrose intake were critical factors during the evolution of 4,6-α-GTs and glucansucrases from α-amylases, allowing oral bacteria to produce extracellular polymers that contribute to biofilm formation from different substrates.

PubMed: 28065507
DOI: 10.1016/j.str.2016.11.023

実験手法

X-RAY DIFFRACTION (1.8 Å)