Detailed analysis of binding sites in the PLL family

E. Fujdiarová1,2, J. Houser1,2, F. Melicher1,2, L. Faltinek1,3, M. Wimmerová1,2,3

1CEITEC – Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 625 00, Czech Republic

2National Centre for Biomolecular Research, Masaryk University, Kamenice 5, Brno, 625 00, Czech Republic

3Department of Biochemistry, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic

Lectins, carbohydrate recognizing proteins, play an important role in various physiological and pathophysiological processes as well as both mutualistic and parasitic interactions between microorganisms and hosts [1]. In connection with the last-mentioned process, lectins from pathogenic bacteria can mediate the first step of infection and our goal is to investigate their specificity and suggest potential inhibitors.

The contribution is focused on the newly described PLL family, specifically on homologous lectins from the bacterium Photorhabdus laumondii.  Photorhabdus spp is known for its complicated life cycle, including mutualism with microscopic nematode and pathogenicity towards insects [2]. Moreover, some species of Photorhabdus are also able to infect humans. Members of the PLL family share a seven-bladed beta-propeller fold and the presence of multiple binding sites within one protein domain [3]. Based on their structural characteristics, binding sites can be divided into two groups; hydrophobic (H) and polar (P). We solved multiple sets of X-ray structures of PLL family lectins in complex with different ligands. The main amino acids involved in the ligand-binding are highly conserved within the lectin family. An in-depth analysis of binding site occupancy was performed to better understand how the difference in amino acid composition within the binding site and its proximity influence the ligand binding.

1. Lis, H. and Sharon, N. Chem Rev. 1998, 98, 637-74.

2. Waterfield NR, Ciche T, Clarke D. Annu Rev Microbiol. 2009,63: 557–574.

3. Fujdiarová E, Houser J, Dobeš P, et al. FEBS J. 2021, 228(4):1343-1365.

This work was supported by GAČR (21-29622S). Experiments performed at Biomolecular Interactions and Crystallization Core Facility are supported by CIISB project of MEYS CR (LM2018127).