SUMMARY PARAGRAPH for SUC5
The S. cerevisiae genome contains seven unlinked loci that encode invertase: SUC1, SUC2, SUC3, SUC4, SUC5, SUC7, and SUC8 (2, 4). This enzyme, also known as "beta-fructofuranosidase," "beta-fructosidase," or "sucrase," plays an important role in sugar metabolism. Invertase catalyzes the hydrolysis of both the disaccharide sucrose (producing the monosaccharides fructose and glucose) and the trisaccharide raffinose (producing fructose and melibiose) (3, 5). All invertase genes except SUC2 are located within telomere sequences (6). Although individual strains may carry any number and combination of SUC genes, the reference strain (S288C) encodes only SUC2 (2) and most recent studies on invertase have focused on that gene.
Invertase played a notable role in early research on basic enzyme function. The colloquial name "invertase" comes from the fact that a solution of sucrose polarizes light in the opposite direction from an equimolar solution of glucose + fructose. This "inversion" of sugar provided a straightforward functional assay which, along with the easy preparation of a periplasmic protein (7 and references therein), made invertase a popular research subject among early biochemists. Many seminal works defining and describing enzymes, including those of Adrian Brown (8) and Leonor Michaelis and Maude Menton (9), focused on invertase.
Invertase also has a role in the food industry where it is used to produce fructose for use in confectionary. Fructose is often preferred over sucrose in candies with soft centers, as it is sweeter and less prone to crystallization (10).
Last updated: 2007-05-22