In enzymology, a 6G-fructosyltransferase (EC is an enzyme that catalyzes the chemical reaction

m+1 alpha-D-glucopyranoside + n+1 alpha-D-glucopyranoside m alpha-D-glucopyranoside + n+1 beta-D-fructofuranosyl-(2->6)-alpha-D-glucopyranoside (m > 0; n > 0)

Thus, the two substrates of this enzyme are m+1 alpha-D-glucopyranoside]] and n+1 alpha-D-glucopyranoside]], whereas its 4 products are m alpha-D-glucopyranoside]], n+1]], ], and 0.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is 1F-oligosucrose 6G-beta-D-fructotransferase. Other names in common use include fructan:fructan 6G-fructosyltransferase, 1F(1-beta-D-fructofuranosyl)m, sucrose:1F(1-beta-D-fructofuranosyl)nsucrose, 6G-fructosyltransferase, 6G-FFT, 6G-FT, and 6G-fructotransferase.