Intracellular catabolism of sucrose (PubMed:2971020). Being intracellular, probably not involved in synthesis of extracellular polysaccharides (Probable). phosphate + sucrose = alpha-D-glucose 1-phosphate + D-fructose Some earlier publications concluded that the product of the reaction of GtfA with sucrose was a glucan, because of its insolubility in ethanol. Belongs to the glycosyl hydrolase 13 family. Sucrose phosphorylase subfamily.