Structural and biochemical analysis of family 92 carbohydrate-binding modules uncovers multivalent binding to β-glucans
Journal article, 2024

Carbohydrate-binding modules (CBMs) are non-catalytic proteins found appended to carbohydrate-active enzymes. Soil and marine bacteria secrete such enzymes to scavenge nutrition, and they often use CBMs to improve reaction rates and retention of released sugars. Here we present a structural and functional analysis of the recently established CBM family 92. All proteins analysed bind preferentially to β−1,6-glucans. This contrasts with the diversity of predicted substrates among the enzymes attached to CBM92 domains. We present crystal structures for two proteins, and confirm by mutagenesis that tryptophan residues permit ligand binding at three distinct functional binding sites on each protein. Multivalent CBM families are uncommon, so the establishment and structural characterisation of CBM92 enriches the classification database and will facilitate functional prediction in future projects. We propose that CBM92 proteins may cross-link polysaccharides in nature, and might have use in novel strategies for enzyme immobilisation.

Author

Meng Shu Hao

AlbaNova University Center

Zhejiang University

Scott Mazurkewich

Chalmers, Life Sciences, Industrial Biotechnology

Wallenberg Wood Science Center (WWSC)

He Li

AlbaNova University Center

Alma Kvammen

AlbaNova University Center

Srijani Saha

AlbaNova University Center

Salla Koskela

AlbaNova University Center

Wallenberg Wood Science Center (WWSC)

Annie R. Inman

AlbaNova University Center

Masahiro Nakajima

Tokyo University of Science

Nobukiyo Tanaka

Tokyo University of Science

Hiroyuki Nakai

Niigata University

Gisela Brändén

University of Gothenburg

Vincent Bulone

AlbaNova University Center

Flinders University

Johan Larsbrink

Chalmers, Life Sciences, Industrial Biotechnology

Wallenberg Wood Science Center (WWSC)

Lauren S McKee

AlbaNova University Center

Wallenberg Wood Science Center (WWSC)

Nature Communications

2041-1723 (ISSN) 20411723 (eISSN)

Vol. 15 1 3429

Subject Categories

Biochemistry and Molecular Biology

Bioprocess Technology

Structural Biology

DOI

10.1038/s41467-024-47584-y

PubMed

38653764

More information

Latest update

7/3/2024 1