5MQS image
Entry Detail
PDB ID:
5MQS
Keywords:
Title:
Sialidase BT_1020
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2016-12-20
Release Date:
2017-03-22
Method Details:
Experimental Method:
Resolution:
3.00 Å
R-Value Free:
0.26
R-Value Work:
0.20
R-Value Observed:
0.21
Space Group:
C 2 2 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Beta-L-arabinobiosidase
Chain IDs:A
Chain Length:1108
Number of Molecules:1
Biological Source:Bacteroides thetaiotaomicron
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
PTR A TYR modified residue
Primary Citation

Abstact

The metabolism of carbohydrate polymers drives microbial diversity in the human gut microbiota. It is unclear, however, whether bacterial consortia or single organisms are required to depolymerize highly complex glycans. Here we show that the gut bacterium Bacteroides thetaiotaomicron uses the most structurally complex glycan known: the plant pectic polysaccharide rhamnogalacturonan-II, cleaving all but 1 of its 21 distinct glycosidic linkages. The deconstruction of rhamnogalacturonan-II side chains and backbone are coordinated to overcome steric constraints, and the degradation involves previously undiscovered enzyme families and catalytic activities. The degradation system informs revision of the current structural model of rhamnogalacturonan-II and highlights how individual gut bacteria orchestrate manifold enzymes to metabolize the most challenging glycan in the human diet.

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Protein

Chemical

Disease

Primary Citation of related structures