Abstract: SHE, a Starch Hydrolytic Enzyme active in maize endosperm (Zea mays), and the cDNA sequence encoding SHE are disclosed. The specificity of native, purified SHE is similar, in general terms, to previously known alpha-amylases. However, the activity of SHE toward amylopectin results in hydrolysis products that are distinctly different from those of other alpha-amylases. SHE, and its homologous equivalents in other plants such as rice, Arabidopsis, apple and potato, can be used in starch processing for generating different, e.g., larger sized, alpha-limit dextrins for industrial use, as compared to those generated by previously known alpha-amylases or other starch hydrolytic enzymes. In addition, modification of the expression of this enzyme in transgenic maize plants or in other transgenic organisms (including bacteria, yeast, and other plant species) can be useful for the generation of novel starch forms or altered starch metabolism.

Abstract: SHE, a Starch Hydrolytic Enzyme active in maize endosperm (Zea mays), and the cDNA sequence encoding SHE are disclosed. The specificity of native, purified SHE is similar, in general terms, to previously known alpha-amylases. However, the activity of SHE toward amylopectin results in hydrolysis products that are distinctly different from those of other alpha-amylases. SHE, and its homologous equivalents in other plants such as rice, Arabidopsis, apple and potato, can be used in starch processing for generating different, e.g., larger sized, alpha-limit dextrins for industrial use, as compared to those generated by previously known alpha-amylases or other starch hydrolytic enzymes. In addition, modification of the expression of this enzyme in transgenic maize plants or in other transgenic organisms (including bacteria, yeast, and other plant species) can be useful for the generation of novel starch forms or altered starch metabolism.

Abstract: SHE, a Starch Hydrolytic Enzyme active in maize endosperm (Zea mays), and the cDNA sequence encoding SHE are disclosed. The specificity of native, purified SHE is similar, in general terms, to previously known alpha-amylases. However, the activity of SHE toward amylopectin results in hydrolysis products that are distinctly different from those of other alpha-amylases. SHE, and its homologous equivalents in other plants such as rice, Arabidopsis, apple and potato, can be used in starch processing for generating different, e.g., larger sized, alpha-limit dextrins for industrial use, as compared to those generated by previously known alpha-amylases or other starch hydrolytic enzymes. In addition, modification of the expression of this enzyme in transgenic maize plants or in other transgenic organisms (including bacteria, yeast, and other plant species) can be useful for the generation of novel starch forms or altered starch metabolism.

Abstract: SHE, a Starch Hydrolytic Enzyme active in maize endosperm (Zea mays), and the cDNA sequence encoding SHE are disclosed. The specificity of native, purified SHE is similar, in general terms, to previously known alpha-amylases. However, the activity of SHE toward amylopectin results in hydrolysis products that are distinctly different from those of other alpha-amylases. SHE, and its homologous equivalents in other plants such as rice, Arabidopsis, apple and potato, can be used in starch processing for generating different, e.g., larger sized, alpha-limit dextrins for industrial use, as compared to those generated by previously known alpha-amylases or other starch hydrolytic enzymes. In addition, modification of the expression of this enzyme in transgenic maize plants or in other transgenic organisms (including bacteria, yeast, and other plant species) can be useful for the generation of novel starch forms or altered starch metabolism.

Abstract: The maize gene dull1 (du1) of the present invention is a determinant of the structure of endosperm starch. Mutations of du1 affect the activity of at least two enzymes involved in starch biosynthesis, namely the starch synthase, SSII, and the starch branching enzyme, SBEIIa. Du1 codes for a predicted 1674 residue protein, and is expressed with a unique temporal pattern in endosperm but is undetectable in leaf or root. The size of the Du1 product and its expression pattern match precisely the known characteristics of maize SSII. The Du1 product contains two different repeated regions in its unique amino terminus, one of which is identical to a conserved segment of the starch debranching enzymes. The cDNA provided for in the present invention encodes SSII, and mutations within this gene affect multiple aspects of starch biogenesis by disrupting an enzyme complex containing starch synthase(s), starch branching enzyme(s), and possibly starch debranching enzyme(s).