Abstract:

A new mannose-binding agglutinin gene was cloned from bulbs of Amaryllis vittata Ait. The full-length cDNA of A. vittata agglutinin (AVA) was 686 bp. The start codon of ava cDNA was at 41-43 bp and the stop codon was at 515-517 bp. Analysis in the BLAST of GenBank showed that ava gene encodes a protein precursor composed of a signal peptide, mature protein and C-terminal amino acid cleavage sequence. The mature protein of AVA includes 109 amino acid residues and the molecular weight is 11.9 kD. The homologous analysis showed that the identity between AVA and Galanthus nivalis agglutinin, Narcissus hybrid cultivar agglutinin, Lycoris radiata agglutinin, Clivia miniata agglutinin are 73.4%, 85.3%, 80.7%, 83.5%, respectively. Molecular modeling of AVA indicated that its three-dimensional structure strongly resembles that of the snowdrop agglutinin. Blocks’ analysis revealed that the deduced amino acid sequence of AVA has three functional domains specific for agglutination and three carbohydrate-binding boxes (QDNY).

Key words: Amaryllis vittata agglutinin (AVA), monocot mannose-binding lectin, degenerate primers, 3' and 5' RACE, homology alignment