Fig. 2.

GlfT2 alone can determine galactan length. The mass spectrum is shown from MALDI-TOF MS analysis of a 20-h incubation of a reaction mixture that contained His₆-GlfT2, UDP-Galf, and compound 5. Peaks that correspond to m/z values of [M + Na]⁺, in which M equals the mass of compound 5 plus n Galf residues, are labeled with the value of n. Unlabeled peaks have m/z values that correspond to the loss of the lipid moiety from elongation products, presumably because of fragmentation. Reaction products are observed from n = 3 to n = 27.