Amino acid sequence alignments of family 13 carbohydrate binding modules. Sequences were deduced from the following GenBank accession numbers: C. cellulans DSM 10297 βglII glucanase (AF052745)  (indicated as C. cellulans 1); C. cellulans ATCC 21606 β-1,3-glucanase (M60826)  (indicated as C. cellulans 2), Ricinus comunis agglutinin β-chain (M12089) , Ricinus comunis ricin β-chain (X52908) , Streptomyces thermoviolaceus xylanase I (AB110643) , Streptomyces lividans α-arabinofuranosidase and xylanase A (M64551) , and Rarobacter faecitabidus Protease I (D10753) . Comparison of the βglII CBM amino acid sequence with related CBMs. The amino acid residues conserved in all of the sequences (boldface), the residues involved in galactose binding in the ricin β-chain subdomains α 1 and γ2, and the corresponding analogous positions in all the subdomains of the aligned sequences (in red), conserved residues that form the hydrophobic core of each ricin β-chain subdomain (in blue), and conserved Cys residues (black background) are marked. Sequence identity values (in %) are referred to the C. cellulans βglII sequence. (A) Sequence similarity of the R1, R2, and R3 subdomains of the βglII CBM, and the subdomains α 1 and γ2 of the ricin β-chain.