InterPro domain: IPR012819

Sucrose occupies a central position in the metabolic pathways of all plants and plays a variety of roles including transport sugar, storage reserve, compatible solute, and signal compound [ 1 ]. This compound is produced by the combined action of two enzymes, sucrose-phosphate synthase ( 2.4.1.14 ) and sucrose-phosphate phosphatase ( 3.1.3.24 ), via the intermediate sucrose 6-phosphate. Several studies have shown a positive correlation between sucrose-phosphate synthase activity and plant growth rate and yield in agronomically important plants, though direct proof of a causal link is lacking.

This entry represents sucrose-phosphate synthase from plants, which is known to exist in multigene families in several species of both monocots and dicots. The enzyme contains an N-terminal domain glucosyltransferase domain, a variable linker region, and a C-terminal domain similar to that of sucrose-phosphate phosphatase, the next and final enzyme of sucrose biosynthesis. The C-terminal domain is likely to serve a binding - not a catalytic - function, as sucrose-phosphate phosphatase is always encoded by a distinct protein.

1. Evolution and function of the sucrose-phosphate synthase gene families in wheat and other grasses. Plant Physiol. 135, 1753-64