9BJX

GH5_4 endo-beta(1,3/1,4)-glucanase from Segatella copri

Summary for 9BJX

• Entry DOI: 10.2210/pdb9bjx/pdb
• Descriptor: Cellulase (Glycosyl hydrolase family 5), 1,2-ETHANEDIOL (3 entities in total)
• Functional Keywords: mixed-linkage beta-glucan, mlg, gh5_4, hydrolase
• Biological source: Segatella copri DSM 18205
• Total number of polymer chains: 4
• Total formula weight: 168317.90

Authors

Cordeiro, R.L.,Golisch, B.,Brumer, H.,Van Petegem, F. (deposition date: 2024-04-25, release date: 2024-10-09)

Primary citation

Golisch, B.,Cordeiro, R.L.,Fraser, A.S.C.,Briggs, J.,Stewart, W.A.,Van Petegem, F.,Brumer, H.
The molecular basis of cereal mixed-linkage beta-glucan utilization by the human gut bacterium Segatella copri.
J.Biol.Chem., 300:107625-107625, 2024

PubMed Abstract: Mixed-linkage β(1,3)/β(1,4)-glucan (MLG) is abundant in the human diet through the ingestion of cereal grains and is widely associated with healthful effects on metabolism and cholesterol levels. MLG is also a major source of fermentable glucose for the human gut microbiota (HGM). Bacteria from the family Prevotellaceae are highly represented in the HGM of individuals who eat plant-rich diets, including certain indigenous people and vegetarians in postindustrial societies. Here, we have defined and functionally characterized an exemplar Prevotellaceae MLG polysaccharide utilization locus (MLG-PUL) in the type-strain Segatella copri (syn. Prevotella copri) DSM 18205 through transcriptomic, biochemical, and structural biological approaches. In particular, structure-function analysis of the cell-surface glycan-binding proteins and glycoside hydrolases of the S. copri MLG-PUL revealed the molecular basis for glycan capture and saccharification. Notably, syntenic MLG-PULs from human gut, human oral, and ruminant gut Prevotellaceae are distinguished from their counterparts in Bacteroidaceae by the presence of a β(1,3)-specific endo-glucanase from glycoside hydrolase family 5, subfamily 4 (GH5_4) that initiates MLG backbone cleavage. The definition of a family of homologous MLG-PULs in individual species enabled a survey of nearly 2000 human fecal microbiomes using these genes as molecular markers, which revealed global population-specific distributions of Bacteroidaceae- and Prevotellaceae-mediated MLG utilization. Altogether, the data presented here provide new insight into the molecular basis of β-glucan metabolism in the HGM, as a basis for informing the development of approaches to improve the nutrition and health of humans and other animals.

PubMed: 39122003
DOI: 10.1016/j.jbc.2024.107625

Experimental method

X-RAY DIFFRACTION (1.6 Å)