5JY7

Complex of Mycobacterium smegmatis trehalose synthase with maltokinase

5JY7 の概要

• エントリーDOI: 10.2210/pdb5jy7/pdb
• 分子名称: Trehalose synthase/amylase TreS, Maltokinase, CALCIUM ION (3 entities in total)
• 機能のキーワード: complex, isomerase, kinase, alpha glucan synthesis, isomerase-transferase complex, isomerase/transferase
• 由来する生物種: Mycobacterium smegmatis (strain ATCC 700084 / mc(2)155); 詳細
• タンパク質・核酸の鎖数: 16
• 化学式量合計: 937307.06

構造登録者

Futterer, K.,Kermani, A.A.,Besra, G.S. (登録日: 2016-05-13, 公開日: 2017-05-24, 最終更新日: 2024-01-10)

主引用文献

Kermani, A.A.,Roy, R.,Gopalasingam, C.,Kocurek, K.I.,Patel, T.R.,Alderwick, L.J.,Besra, G.S.,Futterer, K.
Crystal structure of the TreS-Pep2 complex, initiating alpha-glucan synthesis in the GlgE pathway of mycobacteria.
J.Biol.Chem., 2019

PubMed Abstract: A growing body of evidence implicates the mycobacterial capsule, the outermost layer of the mycobacterial cell envelope, in modulation of the host immune response and virulence of mycobacteria. Mycobacteria synthesize the dominant capsule component, α(1→4)-linked glucan, via three interconnected and potentially redundant metabolic pathways. Here, we report the crystal structure of the TreS:Pep2 complex, containing trehalose synthase (TreS) and maltokinase (Pep2), which converts trehalose to maltose 1-phosphate as part of the TreS:Pep2-GlgE pathway. The structure, at 3.6 Å resolution, revealed that a diamond-shaped TreS tetramer forms the core of the complex and that pairs of Pep2 monomers bind to opposite apices of the tetramer in a 4 + 4 configuration. However, for the orthologues, results from isothermal titration calorimetry and analytical ultracentrifugation experiments indicated that the prevalent stoichiometry in solution is 4 TreS + 2 Pep2 protomers. The observed discrepancy between the crystallized complex and the behavior in the solution state may be explained by the relatively weak affinity of Pep2 for TreS ( 3.5 μm at mildly acidic pH) and crystal packing favoring the 4 + 4 complex. Proximity of the ATP-binding site in Pep2 to the complex interface provides a rational basis for rate enhancement of Pep2 upon binding to TreS, but the complex structure appears to rule out substrate channeling between the active sites of TreS and Pep2. Our findings provide a structural model for the trehalose synthase:maltokinase complex in that offers critical insights into capsule assembly.

PubMed: 30877199
DOI: 10.1074/jbc.RA118.004297

実験手法

X-RAY DIFFRACTION (3.6 Å)