The research is focused on the properties and the structural analysis of the new lectin - saccharide binding protein - from the mushroom Calocera viscosa (CalVL). Mushroom lectins have been variously explored and studied for their potential in biomedicine. Based on lectin-glycan interactions, they exhibit mitogenic, antiproliferative and antimicrobial effects. Various methods were employed to characterize different properties of this lectin. Initial predictions suggested that the CalVL belongs to the family of jacalin-related lectins (JRLs) with a beta-prism fold. JRLs are known for their specificity to D-galactose and D-mannose. The CalVL was produced in E. coli expression system, and purified by affinity chromatography on mannose-agarose resin. Later it was shown by hemagglutination assay that the CalVL can agglutinate erythrocytes due to the interaction with their surface saccharides. Thermostability was determined by Differential Scanning Fluorimetry, homogeneity and the oligomeric state of the protein by Dynamic Light Scattering and Analytical Ultracentrifugation. Crystallization in various screens was performed using the vapour diffusion method, specifically the sitting drop technique. Data collection from obtained crystals was performed on synchrotron PETRAIII. The structure of the CalVL with D-mannose was solved by molecular replacement, where the CalVL without ligand was used as a model. This confirms the prediction of the CalVL being a member of the JRLs family.