5O7U

Crystal structure of the 7-Fluorotryptophan RSL lectin in complex with Lewis x tetrasaccharide

Summary for 5O7U

• Entry DOI: 10.2210/pdb5o7u/pdb
• Related PRD ID: PRD_900119
• Descriptor: Putative fucose-binding lectin protein, alpha-L-fucopyranose-(1-3)-[beta-D-galactopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-L-fucopyranose-(1-3)-[beta-D-galactopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose-(1-3)-alpha-D-galactopyranose, ... (8 entities in total)
• Functional Keywords: lectin, fluorinated tryptophan, lewis x, carbohydrate, sugar binding protein
• Biological source: Ralstonia solanacearum
• Total number of polymer chains: 2
• Total formula weight: 22087.79

Authors

Varrot, A. (deposition date: 2017-06-09, release date: 2018-06-06, Last modification date: 2024-01-17)

Primary citation

Tobola, F.,Lelimousin, M.,Varrot, A.,Gillon, E.,Darnhofer, B.,Blixt, O.,Birner-Gruenberger, R.,Imberty, A.,Wiltschi, B.
Effect of Noncanonical Amino Acids on Protein-Carbohydrate Interactions: Structure, Dynamics, and Carbohydrate Affinity of a Lectin Engineered with Fluorinated Tryptophan Analogs.
ACS Chem. Biol., 13:2211-2219, 2018

PubMed Abstract: Protein-carbohydrate interactions play crucial roles in biology. Understanding and modifying these interactions is of major interest for fighting many diseases. We took a synthetic biology approach and incorporated noncanonical amino acids into a bacterial lectin to modulate its interactions with carbohydrates. We focused on tryptophan, which is prevalent in carbohydrate binding sites. The exchange of the tryptophan residues with analogs fluorinated at different positions resulted in three distinctly fluorinated variants of the lectin from Ralstonia solanacearum. We observed differences in stability and affinity toward fucosylated glycans and rationalized them by X-ray and modeling studies. While fluorination decreased the aromaticity of the indole ring and, therefore, the strength of carbohydrate-aromatic interactions, additional weak hydrogen bonds were formed between fluorine and the ligand hydroxyl groups. Our approach opens new possibilities to engineer carbohydrate receptors.

PubMed: 29812892
DOI: 10.1021/acschembio.8b00377

Experimental method

X-RAY DIFFRACTION (1.15 Å)