Seed lectin similar to type 2 ribosome-inactivating proteins (PubMed:23897472, PubMed:11375527). The Aalpha and Abeta chains constitute the rRNA glycosidase domain and the B chain the carbohydrate-binding lectin domain (PubMed:23897472). Is predicted to have no glycosidase activity and, hence, to be non-toxic, due to small changes in both the nucleotide binding and carbohydrate binding capabilities (PubMed:23897472, PubMed:11375527). Binds galactose and derivatives with a preference for the beta-anomeric forms (PubMed:8799450, PubMed:10877067). Binds prophyrins (PubMed:10877067). Has hemagglutinating activity towards rabbit and human erythrocytes (PubMed:8799450, PubMed:10877067). Heterotrimer consisting of Aalpha, Abeta and B chains with Abeta and B being disulfide-linked. The B chain is composed of two domains with each domain consisting of 3 homologous subdomains (alpha, beta, gamma). The measured range is 1-519. In the N-terminal section; belongs to the ribosome-inactivating protein family. Type 2 RIP subfamily. Was originally thought to be a heterodimer. However, methods used then would have missed the Aalpha chain. Based on similarity to other family members, it is assumed that all three chains derive from a single precursor but the genomic DNA sequence to support this is not yet available.