Bioinformatic analysis of maize gene encoding starch branching enzyme SBEIIb.

A cDNA encoding starch branching enzyme I from maize endosperm.

ADP-Glc pyrophosphorylase (EC 2.7.7.27), starch synthases (EC 2.4.1.21), and SBEs (EC 2.4.1.18) are the key enzymes in the pathway of plant starch biosynthesis. Starch is a polymer of Glc that exists as two fractions, amylose and amylopectin, in maize (Zea mays L.) kernel amyloplasts. The essentially linear polymer amylose contains a-1,4-linked Glc, whereas the branched polymer amylopectin cont...

Genomic organization and promoter activity of the maize starch branching enzyme I gene.

Starch branching enzymes (SBE) which catalyse the formation of alpha-1,6-glucan linkages are of crucial importance for the quantity and quality of starch synthesized in plants. In maize (Zea mays L.), three SBE isoforms (SBEI, IIa and IIb) have been identified and shown to exhibit differential expression patterns. As a first step toward understanding the regulatory mechanisms controlling their ...

Starch-branching enzyme IIa is required for proper diurnal cycling of starch in leaves of maize.

Starch-branching enzyme (SBE), a glucosyl transferase, is required for the highly regular pattern of α-1,6 bonds in the amylopectin component of starch. In the absence of SBEIIa, as shown previously in the sbe2a mutant of maize (Zea mays), leaf starch has drastically reduced branching and the leaves exhibit a severe senescence-like phenotype. Detailed characterization of the maize sbe2a mutant ...

Title: Identification of Multiple Phosphorylation Sites on Maize Endosperm Starch Branching Enzyme IIb, a Key Enzyme in Amylopectin Biosynthesis Running title: Phosphorylation of Starch Branching Enzyme IIb

Nucleotide sequence of a cDNA encoding starch-branching enzyme, or q-enzyme I, from rice endosperm.

The programmed regulation of carbohydrate-metabolizing enzymes is associated with an increase in the production of starch in rice endosperm (4, 5). The increase in starch-branching enzyme, or Q-enzyme, plays a critical role in the initiation and regulation of the biochemical process of starch accumulation in rice endosperm (4) (Table I). Q-enzyme catalyzes the synthesis of amylopectin by introd...