FIGURE 1.

Schematic representation of possible MalQ reactions, starting with maltose as the first possible donor for a sugar unit. For clarity, only glucose and the shorter saccharides maltose, maltotriose, and maltotetraose are considered here. Donor and acceptor molecules are depicted in light blue and yellow, respectively, with their reducing ends highlighted in blue and orange. Notably, the primary reaction products are substrates for subsequent reaction cycles (cf. supplemental material).