A polysaccharide utilization locus from the gut bacterium dysgonomonas mossii encodes functionally distinct carbohydrate esterases
Artikel i vetenskaplig tidskrift, 2021

The gut microbiota plays a central role in human health by enzymatically degrading dietary fiber and concomitantly excreting short chain fatty acids that are associated with manifold health benefits. The polysaccharide xylan is abundant in dietary fiber but noncarbohydrate decorations hinder efficient cleavage by glycoside hydrolases (GHs) and need to be addressed by carbohydrate esterases (CEs). Enzymes from carbohydrate esterase families 1 and 6 (CE1 and 6) perform key roles in xylan degradation by removing feruloyl and acetate decorations, yet little is known about these enzyme families especially with regard to their diversity in activity. Bacteroidetes bacteria are dominant members of the microbiota and often encode their carbohydrate-active enzymes in multigene polysaccharide utilization loci (PULs). Here we present the characterization of three CEs found in a PUL encoded by the gut Bacteroidete Dysgonomonas mossii. We demonstrate that the CEs are functionally distinct, with one highly efficient CE6 acetyl esterase and two CE1 enzymes with feruloyl esterase activities. One multidomain CE1 enzyme contains two CE1 domains: an N-terminal domain feruloyl esterase, and a C-terminal domain with minimal activity on model substrates. We present the structure of the C-terminal CE1 domain with the carbohydrate-binding module that bridges the two CE1 domains, as well as a complex of the same protein fragment with methyl ferulate. The investment of D. mossii in producing multiple CEs suggests that improved accessibility of xylan for GHs and cleavage of covalent polysaccharide-polysaccharide and lignin-polysaccharide bonds are important enzyme activities in the gut environment.

Författare

Cathleen Kmezik

Chalmers, Biologi och bioteknik, Industriell bioteknik

Scott Mazurkewich

Chalmers, Biologi och bioteknik, Industriell bioteknik

Tomke Meents

Lauren S McKee

AlbaNova University Center

Wallenberg Wood Science Center (WWSC)

Alexander Idström

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Lars Evenäs Group

Marina Armeni

Chalmers, Biologi och bioteknik, Systembiologi, CMSI

Otto Savolainen

Itä-Suomen Yliopisto

Chalmers, Biologi och bioteknik, Systembiologi, CMSI

Gisela Brändén

Göteborgs universitet

Johan Larsbrink

Chalmers, Biologi och bioteknik, Industriell bioteknik

Wallenberg Wood Science Center (WWSC)

Journal of Biological Chemistry

0021-9258 (ISSN) 1083-351X (eISSN)

Vol. 296 100500

Utveckling av en konsoliderad bioprocess för omvandling av växtbiomassa till mångsidiga kemiska byggstenar

ÅForsk, 2017-07-01 -- 2018-05-31.

Vetenskapsrådet (VR), 2017-01-01 -- 2020-12-31.

Novo Nordisk Fonden, 2018-01-01 -- 2020-12-31.

Ämneskategorier

Biokemi och molekylärbiologi

Strukturbiologi

Biokatalys och enzymteknik

Styrkeområden

Materialvetenskap

DOI

10.1016/j.jbc.2021.100500

PubMed

33667545

Mer information

Senast uppdaterat

2021-05-05