Journal:Acta Cryst F:S2053230X25003905

Crystal structure of a recombinant mushroom Agaricus bisporus mannose-binding protein with a longer C-terminal region

Dr Hiromi Yoshida ^[1]

Molecular Tour
Agaricus bisporus mannose-binding protein (Abmb, 150 residues) is a ricin B-like type lectin, which has a beta-trefoil fold. Previously reported recombinant C-terminal His-tagged Abmb (additional 12 residues + 6 x His-tag, Abmb168h) showed specific binding activity to mannose and mannitol in surface plasmon resonance analysis. The structure of a recombinant Abmb including additional six residues at the C-terminus after cleavage by TEV protease (Abmb156, PDB code: 5eha) has been reported, however, carbohydrate binding site of Abmb has not yet been determined. The present structure of a recombinant Abmb with a longer C-terminal region (14 residues + 6 x His-tag, Abmb170h, crystalized in two forms, orthorhombic (PDB code: 9udy) and monoclinic (PDB code: 9udz) showed high flexibility of several surface loop regions including C-terminal tail. This recombinant Abmb170h did not show binding affinity toward alpha-D-mannose but showed weak binding affinity toward GalNAc and beta-D-galactose in glycan search assay. The structure of Abmb170h reveals that the C-terminal region has an impact on the sugar binding and would be important to the mannose binding affinity. This can be seen in the comparison of the two Abmb170h structures versus Abmb156.

• Structures of 9udy vs ABmb156 5eha and animation
• Structures of Abmb170h Monoclinc (chain A) 9udy in which some loops are not seen vs ABmb156 5eha and animation
• While structures of Abmb170h Orthorhombic 9udy vs Abmb170h Monoclinc (chain A) 9udy and animation look very similary.

References

1. ↑ Yoshida H, Nakakita SI, Rachmawati H, Tjandrawinata RR, Ismaya WT. Crystal structure of a recombinant Agaricus bisporus mushroom mannose-binding protein with a longer C-terminal region. Acta Crystallogr F Struct Biol Commun. 2025 Jun 1. PMID:40349189 doi:10.1107/S2053230X25003905