8QJ5

Crystal structure of the Levansucrase beta from Pseudomonas syringae pv. actinidiae

Summary for 8QJ5

• Entry DOI: 10.2210/pdb8qj5/pdb
• Descriptor: Glutamate 5-kinase, PHOSPHATE ION, polyethylene glycol, ... (8 entities in total)
• Functional Keywords: beta-propeller, levan, glycoside hydrolase, transferase
• Biological source: Pseudomonas syringae pv. actinidiae
• Total number of polymer chains: 2
• Total formula weight: 97513.86

Authors

Ferraroni, M.,Peritore, L. (deposition date: 2023-09-12, release date: 2024-09-25, Last modification date: 2025-10-15)

Primary citation

Cicchi, C.,Pazzagli, L.,Paoli, P.,Campigli, S.,Marchi, G.,Cardona, F.,Clemente, F.,Pavone, S.,Ferraroni, M.,Canovai, A.,Matassini, C.,Luti, S.
Molecular Basis of Pseudomonas syringae pv actinidiae Levansucrase Inhibition by a Multivalent Iminosugar.
J.Agric.Food Chem., 73:15981-15992, 2025

PubMed Abstract: Levansucrases are a class of polysaccharide-processing enzymes widely distributed among plant pathogenic bacteria, such as and . Therefore, the modulation of levansucrase activity could represent a new strategy to reduce the microbial survival of such bacteria. Herein, we identified a tetravalent pyrrolidine iminosugar (TPIS) as the first levansucrase inhibitor described to date. TPIS reversibly inhibits sucrose hydrolysis and levan polymerization of levansucrase derived from different bacterial genotypes of , showing competitive behavior and an inhibition constant () in the micromolar range. Interestingly, the monovalent pyrrolidine iminosugar (PIS) analogue shows negligible inhibition, suggesting that multivalency plays a pivotal role in the interaction with levansucrase. To gain insight into the binding mechanism, the X-ray crystal structures of the beta levansucrase isoform from pv (Psa) in its native form and in complex with TPIS were solved, confirming TPIS as a competitive inhibitor of levansucrases. Only a portion of TPIS, corresponding to one chain of the tetravalent iminosugar derivative, was visible in the electron density maps. Nevertheless, our structural data provided an adequate comprehension of the inhibitor/enzyme interactions, sufficient to exclude some of the possible inhibition mechanisms justifying a multivalent effect and pave the way for the development of new, more potent inhibitors.

PubMed: 40349214
DOI: 10.1021/acs.jafc.5c01947

Experimental method

X-RAY DIFFRACTION (1.63 Å)