When LecB Is Not Alone: Structural and Functional Analysis of a Two-Domain Lectin
| Authors | |
|---|---|
| Year of publication | 2026 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | LecB (PA-IIL) is one of two well-characterized lectins from the opportunistic pathogen Pseudomonas aeruginosa and plays a key role in host colonization and biofilm formation, particularly in immunocompromised patients such as those with cystic fibrosis [1]. Homologous lectins have also been identified in other pathogenic bacteria, including Burkholderia cenocepacia [2]. Notably, several uncharacterized LecB-like proteins contain an additional N-terminal domain of unknown function, suggesting potential functional diversification within this lectin family. This project aims to structurally and functionally characterize a putative two-domain lectin comprising a canonical LecB-like carbohydrate-binding domain and an N-terminal accessory domain. A candidate gene encoding such a protein from an insect pathogen was identified through bioinformatic analysis, cloned into expression vectors, and expressed in E. coli. In addition to full-length constructs, individual domains were expressed separately to enable domain-specific characterization. Purified proteins are being analyzed using biophysical methods to assess oligomeric state, thermostability, and sample homogeneity, and their carbohydrate-binding properties are under investigation. Extensive crystallization screening was performed for both full-length proteins and isolated domains. The structure of the N-terminal domain has been largely determined by molecular replacement and is currently undergoing refinement. Crystallization of the LecB-like domain is still being optimized. However, comparative analysis of predicted structures with canonical LecB suggests potential differences in ligand-binding architecture that may reflect altered specificity or regulatory function. These findings provide new insight into the structural diversity of LecB-like lectins and contribute to understanding bacterial adhesion mechanisms in pathogenic bacteria. |
| Related projects: |