Narcissus and Daffodil

Narcissus lectins 385
Figure 16.2 (A) Deduced amino acid sequence of the narcissus lectin precursor encoded
by cDNA clone LECNPA1. The arrow indicates the cleavage site of the
signal peptide. (B) Internal sequence similarity of different segments of the
mature narcissus lectin sequence of 109 amino acids. The amino acids
composing the carbohydrate-binding site are indicated in bold.
Figure 16.3 Three-dimensional structure of the narcissus lectin monomer. Strands of
antiparallel β-sheet are represented by arrows. Asterisks indicate the location
of the monosaccharide binding site.
mannose-binding sites are perfectly conserved and that the narcissus lectin
subunits also contain three functional carbohydrate-binding sites. Hence, as in
snowdrop, the narcissus lectin monomer possesses three mannose-binding sites,
each composed of four amino acid residues, Gln, Asp, Asn and Tyr, that bind O2