| RRC ID |
66784
|
| 著者 |
Miyake M, Terada T, Shimokawa M, Sugimoto N, Arakawa T, Shimizu K, Igarashi K, Fujita K, Fushinobu S.
|
| タイトル |
Structural analysis of β-L-arabinobiose-binding protein in the metabolic pathway of hydroxyproline-rich glycoproteins in Bifidobacterium longum.
|
| ジャーナル |
FEBS J
|
| Abstract |
Bifidobacterium longum is a symbiotic human gut bacterium that has a degradation system for β-arabinooligosaccharides, which are present in the hydroxyproline-rich glycoproteins of edible plants. Whereas microbial degradation systems for α-linked arabinofuranosyl carbohydrates have been extensively studied, little is understood about the degradation systems targeting β-linked arabinofuranosyl carbohydrates. We functionally and structurally analyzed a substrate-binding protein (SBP) of a putative ABC transporter (BLLJ_0208) in the β-arabinooligosaccharide degradation system. Thermal shift assays and isothermal titration calorimetry revealed that the SBP specifically bound Araf-β1,2-Araf (β-Ara2 ) with a Kd of 0.150 μm, but did not bind L-arabinose or methyl-β-Ara2 . Therefore, the SBP was termed β-arabinobiose-binding protein (BABP). Crystal structures of BABP complexed with β-Ara2 were determined at resolutions of up to 1.78 Å. The findings showed that β-Ara2 was bound to BABP within a short tunnel between two lobes as an α-anomeric form at its reducing end. BABP forms extensive interactions with β-Ara2 , and its binding mode was unique among SBPs. A molecular dynamics simulation revealed that the closed conformation of substrate-bound BABP is stable, whereas substrate-free form can adopt a fully open and two distinct semi-open states. The importer system specific for β-Ara2 may contribute to microbial survival in biological niches with limited amounts of digestible carbohydrates. DATABASE: Atomic coordinates and structure factors (codes 6LCE and 6LCF) have been deposited in the Protein Data Bank (http://wwpdb.org/).
|
| 巻・号 |
287(23)
|
| ページ |
5114-5129
|
| 公開日 |
2020-12-1
|
| DOI |
10.1111/febs.15315
|
| PMID |
32246585
|
| MeSH |
Bacterial Proteins / chemistry*
Bacterial Proteins / metabolism
Bifidobacterium longum / isolation & purification
Bifidobacterium longum / metabolism*
Carrier Proteins / chemistry*
Carrier Proteins / metabolism
Crystallography, X-Ray
Disaccharides / metabolism*
Glycoproteins / chemistry*
Glycoproteins / metabolism
Humans
Hydroxyproline / metabolism
Metabolic Networks and Pathways
Models, Molecular
Protein Conformation
Substrate Specificity
|
| リソース情報 |
| 一般微生物 |
JCM1217 |
