Single- and two-chain legume lectins as phylogenetic markers of speciation

The amino acid sequences of various single- and two-chain lectins from the Leguminosae exhibit striking homologies which indicates that these proteins have been conserved during evolution. Their predicted secondary structures appear to be very similar to that of Con A and, in addition, amino acids involved in the three major functional features of the Con A protomer (hydrophobic cavity, bivalent cation binding sites and carbohydrate binding site) are well conserved in other single- and two-chain lectins. It is assumed that Vicieae and Leguminosae lectins are, like Con A, three-domain proteins whose amino acid sequences have been slightly modified during evolution, thus appearing as good phylogenetic markers of speciation.