Figure 7.

N-Terminal Sequence Analysis of Polypeptides Accumulated in βVPE::dSpm1 Seeds.

At left is a SDS-PAGE 4 to 20% mini-gel comparing mature seed protein of homozygous βVPE::dSpm1 (β) and the wild type (C) to indicate the polypeptide bands sequenced. The boxes at right show the alignment of the identified N-terminal sequence for each polypeptide band with respect to the corresponding full-length seed storage protein. Arrowheads illustrate cleavage sites resulting in mature seed storage protein chains. Arrowheads with darts indicate N-termini identified at sites consistent with signal peptidase cleavage, and arrowheads with asterisks indicate N termini identified at sites consistent with processing using purified Asp protease in vitro.