Structure and interactions of the phloem lectin (phloem protein 2) Cus17 from Cucumis sativus

Bobbili, KB and Sivaji, N and Priya, B and Suguna, K and Surolia, A (2023) Structure and interactions of the phloem lectin (phloem protein 2) Cus17 from Cucumis sativus. In: Structure, 31 (4). 464-479.e5.

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Abstract

Phloem protein 2 (PP2) contributes crucially to phloem-based defense in plants by binding to carbohydrates displayed by pathogens. However, its three-dimensional structure and the sugar binding site remained unexplored. Here, we report the crystal structure of the dimeric PP2 Cus17 from Cucumis sativus in its apo form and complexed with nitrobenzene, N-acetyllactosamine, and chitotriose. Each protomer of Cus17 consists of two antiparallel four-stranded twisted β sheets, a β hairpin, and three short helices forming a β sandwich architectural fold. This structural fold has not been previously observed in other plant lectin families. Structure analysis of the lectin-carbohydrate complexes reveals an extended carbohydrate binding site in Cus17, composed mostly of aromatic amino acids. Our studies suggest a highly conserved tertiary structure and a versatile binding site capable of recognizing motifs common to diverse glycans on plant pathogens/pests, which makes the PP2 family suited for phloem-based plant defense.

Item Type:	Journal Article
Publication:	Structure
Publisher:	Cell Press
Additional Information:	The copyright for this article belongs to Cell Press.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	21 Apr 2023 10:28
Last Modified:	21 Apr 2023 10:28
URI:	https://eprints.iisc.ac.in/id/eprint/81369

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