8IC6

exo-beta-D-arabinanase ExoMA2 from Microbacterium arabinogalactanolyticum in complex with Tris

8IC6 の概要

• エントリーDOI: 10.2210/pdb8ic6/pdb
• 分子名称: exo-beta-D-arabinanase, MAGNESIUM ION, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL, ... (7 entities in total)
• 機能のキーワード: glycoside hydrolase, hydrolase
• 由来する生物種: Microbacterium arabinogalactanolyticum
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 191592.59

構造登録者

Fukushima, R.,Kashima, T.,Ishiwata, A.,Fujita, K.,Fushinobu, S. (登録日: 2023-02-10, 公開日: 2023-08-16, 最終更新日: 2023-09-27)

主引用文献

Shimokawa, M.,Ishiwata, A.,Kashima, T.,Nakashima, C.,Li, J.,Fukushima, R.,Sawai, N.,Nakamori, M.,Tanaka, Y.,Kudo, A.,Morikami, S.,Iwanaga, N.,Akai, G.,Shimizu, N.,Arakawa, T.,Yamada, C.,Kitahara, K.,Tanaka, K.,Ito, Y.,Fushinobu, S.,Fujita, K.
Identification and characterization of endo-alpha-, exo-alpha-, and exo-beta-D-arabinofuranosidases degrading lipoarabinomannan and arabinogalactan of mycobacteria.
Nat Commun, 14:5803-5803, 2023

PubMed Abstract: The cell walls of pathogenic and acidophilic bacteria, such as Mycobacterium tuberculosis and Mycobacterium leprae, contain lipoarabinomannan and arabinogalactan. These components are composed of D-arabinose, the enantiomer of the typical L-arabinose found in plants. The unique glycan structures of mycobacteria contribute to their ability to evade mammalian immune responses. In this study, we identified four enzymes (two GH183 endo-D-arabinanases, GH172 exo-α-D-arabinofuranosidase, and GH116 exo-β-D-arabinofuranosidase) from Microbacterium arabinogalactanolyticum. These enzymes completely degraded the complex D-arabinan core structure of lipoarabinomannan and arabinogalactan in a concerted manner. Furthermore, through biochemical characterization using synthetic substrates and X-ray crystallography, we elucidated the mechanisms of substrate recognition and anomer-retaining hydrolysis for the α- and β-D-arabinofuranosidic bonds in both endo- and exo-mode reactions. The discovery of these D-arabinan-degrading enzymes, along with the understanding of their structural basis for substrate specificity, provides valuable resources for investigating the intricate glycan architecture of mycobacterial cell wall polysaccharides and their contribution to pathogenicity.

PubMed: 37726269
DOI: 10.1038/s41467-023-41431-2

実験手法

X-RAY DIFFRACTION (1.75 Å)