A Novel Gene Contributing to the Initiation of Fatty Acid Biosynthesis in Escherichia coli

Abstract

Fatty acid biosynthesis is an essential process conserved across life forms. β-Ketoacyl-ACP synthases are essential for fatty acid biosynthesis. FabH is a β-ketoacyl-ACP synthase that contributes to the initiation of fatty acid biosynthesis in Escherichia coli . In this study, we present genetic and biochemical evidence that the yiiD (renamed fabY )-encoded function contributes to the biosynthesis of fatty acid in the absence of FabH activity and that under these conditions, the expression of FabY was regulated by the stringent response factors (p)ppGpp and DksA. Combined inactivation of FabH and FabY resulted in growth arrest, possibly due to the loss of fatty acid biosynthesis. A molecule(s) that inhibits the two activities can be an effective microbicide.