Fig. 2: The KS–LD–MAT domains of LovB.

a The model of the domains is shown in top view, with the substrate binding tunnel represented in cyan surface. b Top, close-up view of the disconnected catalytic tunnel of KS. The conserved active site residues are labeled. Two additional residues (M132 and F436) intercept the acyl (inner) and PPant (outer) pockets. Middle and bottom, the long traversing-through substrate tunnels of KS domains from mFAS and DEBS.