Lectins are proteins and glycoproteins able to reversibly bind saccharide moieties of glycoconjugates with high specificity. Lectins are involved in many physiological processes and play crucial roles in cell-cell communication or recognition of the host by a pathogen [1]. The research is focused on the lectins produced by the Gram-negative bacteria Photorhabdus laumondii. Bacteria of Photorhabdus genus live in symbiosis with Heterorhabditis nematodes. This symbiotic complex can be found in soil, where it searches for insect prey [2].
Unusual dual behaviour makes Photorhabdus bacterium a compelling organism for further study of its biomolecules. Besides functional characterization, structural information is essential for discovering the number of binding sites, the key residues involved in interaction and the orientation of the binding partner. For this purpose, protein crystallography was used to determine the 3D structure of lectin PLU1 and its complex with binding partners in atomic resolution. Examination of the PLU1 structure revealed a unique binding pocket, which significantly impacts the binding properties of the PLU1.
This work was supported by the Czech Science Foundation (21-29622S) and CIISB research infrastructure project LM2018127 funded by MEYS CR.