fig1

Figure 1. Molecular dissection of the Sus system of B. thetaiotaomicron involved in degrading dietary starch. When the SusG α-amylase enzyme is active (panel A), starch bound to the cell surface by starch-binding proteins is degraded, releasing oligosaccharides that are transported into the periplasm (SusC) and further degraded by periplasmic enzymes (SusA and SusB) prior to final uptake of monomeric units into the cell. When the susG gene is knocked out (panel B), starch bound to the cell surface is not degraded and there is no uptake and further degradation.