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 3429Subject Categories
Biochemistry and Molecular Biology
Bioprocess Technology
Structural Biology
DOI
10.1038/s41467-024-47584-y
PubMed
38653764