CLONING AND CHARACTERIZATION OF A CDNA-ENCODING AN ANTIMICROBIAL CHITIN-BINDING PROTEIN FROM AMARANTH, AMARANTHUS-CAUDATUS

A cDNA clone encoding an antimicrobial chitin-binding protein from ama ranth (Amaranthus caudatus L.) was isolated using a cDNA library const ructed from near-mature seed poly(A)+ mRNA. The deduced amino acid seq uence of the cDNA clone encodes a predicted polypeptide of 86 amino ac ids. This polypeptide has three distinct domains: an amino-terminal pu tative signal peptide (25 amino acids), a domain corresponding to the mature protein (30 amino acids), and a carboxyl-terminal propeptide (3 1 amino acids) containing a putative N-glycosylation site. The encoded protein differs from all known members of the family of chitin-bindin g proteins. Transcripts of the expected size (650 bp) are present in d eveloping seeds but not in roots, leaves or stressed leaves.