Molecular cloning and expression analysis of novel wheat cysteine protease.

A cDNA clone encoding a novel papain-like cysteine protease was isolated from wheat germ (Triticum aestivum). This cDNA encoded a 371-residue protein, designated WCP2, composed of signal peptide followed by a propeptide and a mature protease containing active site residues that are highly conserved among the papain family. The mature WCP2 protein (26 kDa) was detected in the quiescent embryo and its level of expression in the germinating embryo was greatly increased.