9VBY
Lectin FRIL from Lablab purpureus with self glycan
Summary for 9VBY
| Entry DOI | 10.2210/pdb9vby/pdb |
| Related | 9VBW 9VBX 9VBZ 9VC0 |
| EMDB information | 64936 |
| Descriptor | Flt3 receptor-interacting lectin, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose, CALCIUM ION, ... (5 entities in total) |
| Functional Keywords | flt3 receptor-interacting lectin, carbohydrate binding protein, lectin, glycoprotein, self glycan, fril, plant protein |
| Biological source | Lablab purpureus (hyacinth bean) |
| Total number of polymer chains | 4 |
| Total formula weight | 117003.78 |
| Authors | Nguyen, V.H.T.,Liu, Y.M.,Chen, X.,Ma, C. (deposition date: 2025-06-05, release date: 2026-03-18, Last modification date: 2026-04-29) |
| Primary citation | Liu, Y.M.,Nguyen, H.T.V.,Chen, X.,Shahed-Al-Mahmud, M.,Chen, T.H.,Liao, K.S.,Lo, J.M.,Kan, T.C.,Ren, C.T.,Ma, C. Altering the carbohydrate-binding specificity of the legume lectin FRIL through structure-guided engineering. Nat Commun, 17:-, 2026 Cited by PubMed Abstract: FRIL is a legume lectin from the hyacinth bean that has broad-spectrum antiviral activity. A distinctive trait of FRIL among similar mannose/glucose-specific legume lectins is that FRIL shows specificity for complex type N-glycans. We postulate that an extended binding site on FRIL facilitates this ligand selectivity. Here, we show legume lectin carbohydrate recognition domain (CRD) loop B is the main determinant of complex versus high-mannose N-glycan specificity in FRIL and Concanavalin A (ConA), respectively. First, we find that the inactive precursors of recombinant FRIL (rFRIL) and proConA (rproConA) can be activated via deglycosylation. Secondly, the cryo-EM structures of inactive apo rFRIL, active FRIL in complex with Galβ1,4-(Fucα1,3-)GlcNAcβ1,2-Man tetrasaccharide, and active rFRIL in complex with MannoseGlcNAc (Man9) N-glycan are determined, and residues H102 and Y101 on loop B are identified as crucial for complex glycan recognition. Finally, we swapped loop B residues 101 and 102 alongside loop C residue 145 on FRIL to their structural equivalent on ConA, resulting in a FRIL mutant that binds exclusively to high mannose N-glycans. Taken together, we have established a process of activating recombinant FRIL and related lectins through deglycosylation, and demonstrated the crucial role that loop B residues play in establishing oligosaccharide specificity. PubMed: 41786775DOI: 10.1038/s41467-026-70188-7 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.67 Å) |
Structure validation
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