8QX6

Novel laminarin-binding CBM X584

Summary for 8QX6

• Entry DOI: 10.2210/pdb8qx6/pdb
• Descriptor: PKD domain-containing protein, beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: cbm x584, surface glycan binding protein, carbohydrate binding module, ligand complex, sugar binding protein
• Biological source: Christiangramia forsetii KT0803
• Total number of polymer chains: 2
• Total formula weight: 37193.83

Authors

Zuehlke, M.K.,Jeudy, A.,Czjzek, M. (deposition date: 2023-10-22, release date: 2024-09-18)

Primary citation

Zuhlke, M.K.,Ficko-Blean, E.,Bartosik, D.,Terrapon, N.,Jeudy, A.,Jam, M.,Wang, F.,Welsch, N.,Durwald, A.,Martin, L.T.,Larocque, R.,Jouanneau, D.,Eisenack, T.,Thomas, F.,Trautwein-Schult, A.,Teeling, H.,Becher, D.,Schweder, T.,Czjzek, M.
Unveiling the role of novel carbohydrate-binding modules in laminarin interaction of multimodular proteins from marine Bacteroidota during phytoplankton blooms.
Environ.Microbiol., 26:e16624-e16624, 2024

PubMed Abstract: Laminarin, a β(1,3)-glucan, serves as a storage polysaccharide in marine microalgae such as diatoms. Its abundance, water solubility and simple structure make it an appealing substrate for marine bacteria. Consequently, many marine bacteria have evolved strategies to scavenge and decompose laminarin, employing carbohydrate-binding modules (CBMs) as crucial components. In this study, we characterized two previously unassigned domains as laminarin-binding CBMs in multimodular proteins from the marine bacterium Christiangramia forsetii KT0803, thereby introducing the new laminarin-binding CBM families CBM102 and CBM103. We identified four CBM102s in a surface glycan-binding protein (SGBP) and a single CBM103 linked to a glycoside hydrolase module from family 16 (GH16_3). Our analysis revealed that both modular proteins have an elongated shape, with GH16_3 exhibiting greater flexibility than SGBP. This flexibility may aid in the recognition and/or degradation of laminarin, while the constraints in SGBP could facilitate the docking of laminarin onto the bacterial surface. Exploration of bacterial metagenome-assembled genomes (MAGs) from phytoplankton blooms in the North Sea showed that both laminarin-binding CBM families are widespread among marine Bacteroidota. The high protein abundance of CBM102- and CBM103-containing proteins during phytoplankton blooms further emphasizes their significance in marine laminarin utilization.

PubMed: 38757353
DOI: 10.1111/1462-2920.16624

Experimental method

X-RAY DIFFRACTION (1.9 Å)