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Based on our biochemical evidence of glycan binding (and the high sequence similarity between MU1 and MU3), we suggest that MG1, MN3 and MU1/MU3 domains be annotated as new CBMs in the CAZy database. Future studies can focus on how these glycan binding domains compare with existing LacNAc binding galectins21,64 and Siaα2-6 binding proteins such as the human influenza A and B virus lectin haemagglutinin65, Pseudomonas aeruginosa pili66, the surface protein antigen (PAc) of Streptococcus mutans67, mushroom Polyporus squamosus agglutinin (PSA)68, and the plant lectins, Sambucus nigra agglutinin (SNA), Sambucus canadensis agglutinin (SCA), Sambucus sieboldiana agglutinin (SSA), Wheat-germ agglutinin (WGA), Trichosanthes japonica (TJA-I), and ML-I of Viscum album69,70,71,72,6 Gal beta 1->4GlcNAc and HSO3(-)- > 6Gal beta 1->GlcNAc specific lectin in tuberous roots of Trichosanthes japonica. Biochemistry 31, 11647–11650 (1992)." href="/articles/s42003-023-04718-0#ref-CR73" id="ref-link-section-d78971106e2617"73./p>144 bp (which is the size of the amplicon expected for a non-recombinant phage amplified by the T7UP and T7DOWN primers) were considered to be recombinant. Enriched recombinant phages were further subjected to Sanger sequencing in-house (at IMTECH, using 16-capillary 3130xl Genetic Analyzer, Applied Biosystems). DNA sequences obtained were translated using ExPASy80 and visualized using FinchTV version 1.4.0. Sequences with more than 30 continuous amino acids (without any stop codon) were considered for further analysis. These metagenomic sequences were subjected to searches against both the protein sequence database, ‘UniRef100’81, and the profile databases, ‘pfamA-full’ and ‘pfamB’31, and ‘dbCAN2’33 using mmseqs282 at a very high sensitivity (-s 8.5). In addition, an all-against-all sequence search of the initial 33 query proteins was also performed. The general command run for these searches was ‘mmseqs easy-search input_protein_seqs search_database output.result_file tmp_directory -s 8.5 --format-mode 2‘. In the search against UniRef100, for each query protein sequence, the top five returned hits were retained and were then further searched for pfamA-full domains as above using mmseqs2. The fields ‘representativeMember_organismName‘ and ‘cluster_representative_name‘ (in Table S5) were obtained using uniprot API81. In the search result against pfamA-full, the field ‘pfam-family_description‘ (in Table S7) was obtained using https://github.com/AlbertoBoldrini/python-pfam (a python interface for pfamA). Three-dimensional structure predictions were performed for all amino acid sequences using a local server installed AlphaFold2, and structures were visualized using reverse rainbow coloring based on pLDDT scores in PyMOL (Schrodinger) (Supplementary Data 2)./p>6 Gal beta 1->4GlcNAc and HSO3(-)- > 6Gal beta 1->GlcNAc specific lectin in tuberous roots of Trichosanthes japonica. Biochemistry 31, 11647–11650 (1992)./p>