Figure 9: Proposed N-acyltransferase reaction mechanism in Lnt.

Electron lone pairs shown as double dots. (a) First Michaelis complex with 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) substrate. (b) First tetrahedral intermediate. Tetrahedral carbon shown in stereochemical representation. The oxyanion bears a negative charge. (c) Second Michaelis complex with apo-lipoprotein substrate. (d) Second tetrahedral intermediate. (e) Product complex. (f) Empty active site ready to undergo another reaction cycle. Red curved arrows indicate electron flow. Dashed blue lines denote oxyanion stabilization. GPE, glyceryl-phosphoethanolamine; LP, apo-lipoprotein; DAG, diacylglyceryl; LPE, lyso-PE.