Involved in the biosynthesis of the enzyme cofactor mycofactocin (MFT). Acts as a glycosyltransferase that catalyzes the oligoglycosylation of pre-mycofactocin (PMFT), adding up to nine beta-1,4-linked glucose residues (PubMed:33014324). Is required for the in vivo ethanol assimilation in M.smegmatis (PubMed:31113891). Cells lacking this gene lose the ability to utilize ethanol as the sole growth substrate (PubMed:31113891). Glycosylated mycofactocins are not detected in this mutant, as well as PMFT and PMFTH(2) (PubMed:33014324). Belongs to the glycosyltransferase 2 family.