Figure 3: Aligned amino acid sequences of RBL-CRDs. Multiple alignment was achieved using the CLUSTAL X program. Secondary structural elements are shown as cylinders (α helix, α1–α3) and arrows (β strand, β1–β5). Disulfide-bond paring of eight half-cystine residues (C1–C8) is indicated at the bottom. Bold-faced amino acids indicate the residues involved in the carbohydrate binding. The sequence data were obtained from the Entrez protein sequence database including SwissProt, PIR, PRF, and PDB. The CRDs located in the N-terminal, middle, and C-terminal regions are represented by N, M, and C, respectively. CSL: chum salmon (Oncorhynchus keta) egg lectin, OLL: shishamo smelt (Osmerus lanceolatus) egg lectin, PFL: ponyfish (Leiognathus nuchalis) egg lectin, PPL: penguin wing oyster (Pteria penguin) lectin, SAL: catfish (Silurus asotus) egg lectin, SFL: ayu (Pleacoglossus altivelis) egg lectin, SML: Spanish mackerel (Scomberomorous niphonius) egg lectin, STL: steelhead trout (Oncorhynchus mykiss) egg lectin, SUEL: sea urchin (Anthocidaris crassispina) egg lectin, TBL: far east dace (Tribolodon brandti) egg lectin, WCL: white spotted charr (Salvelinus leucomaenis) egg lectin. Bs: Botryllus schlosseri, Ca: snakehead (Channa argus), Ci: Ciona intestinalis, Dr: zebrafish (Danio rerio), El: northern pike (Esox lucius), Hk: spotted seahorse (Hippocampus kuda), Hm: Hydra magnipapillata, If: blue catfish (Ictalurus furcatus), Ls: humphead snapper (Lutjanus sanguineus), Mm: house mouse (Mus musculus), Ot: small-eared galago (Otolemur garnettii), Sp: Strongylocentrotus purpuratus, Ss: Atlantic salmon (Salmo salar), Tn: green pufferfish (Tetraodon nigroviridis).