Fig. 7. Model of membrane association mechanism of PatA.

(A to C) The N-terminal helices α1 and α2 and the polarity of PatA determines the right orientation of the enzyme on the membrane. PIM₂ is anchored into the inner leaflet of the mycobacterial IM. C16-CoA is localized in the cytosol. (B to D) PatA sequesters the acyl chain of the acyl-CoA donor substrate from the cytosol and incorporates it into a hydrophobic tunnel that extends entirely through the core of the enzyme. In this orientation, the polar head of PIM₂ enters into a cavity located in the major groove to react with the acyl-CoA, at the protein-membrane interphase. The Ac₁PIM₂ product is formed and CoA-SH is released to the cytosol.