Cloning and sequencing of a cDNA encoding a heat-stable sweet protein, mabinlin II.

A cDNA clone encoding a heat-stable sweet protein, mabinlin II (MAB), was isolated and sequenced. The encoded precursor to MAB was composed of 155 amino acid (aa) residues, including a signal sequence of 20 aa, an N-terminal extension peptide of 15 aa, a linker peptide of 14 aa and one residue of C-terminal extension. Comparison of the proteolytic cleavage sites during post-translational processing of MAB precursor with those of like 2S seed-storage proteins of Arabidopsis thaliana, Brassica napus and Bertholletia excelsa shows that the three individual cleavage sites between respective species are conserved.