Cell division factor ZapE regulates biofilm formation by impacting the quorum sensing system.

is one of the leading nosocomial pathogens that causes both severe acute and chronic infections. The strong capacity of to form biofilms can dramatically increase its antibiotic resistance and lead to treatment failure. The biofilm resident bacterial cells display distinct gene expression profiles and phenotypes compared to their free-living counterparts. Elucidating the genetic determinants of biofilm formation is crucial for the development of antibiofilm drugs. In this study, a high-throughput transposon-insertion site sequencing (Tn-seq) approach was employed to identify novel biofilm genetic determinants. When analyzing the novel biofilm regulatory genes, we found that the cell division factor ZapE (PA4438) controls the quorum sensing system. The ∆ mutant lost fitness against the wild-type PAO1 strain in biofilms and its production of 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS) had been reduced. Further biochemical analysis showed that ZapE interacts with PqsH, which encodes the synthase that converts 2-heptyl-4-quinolone (HHQ) to PQS. In addition, site-directed mutagenesis of the ATPase active site of ZapE (K72A) abolished the positive regulation of ZapE on PQS signaling. As ZapE is highly conserved among the group, our study suggests that it is a potential drug target for the control of infections.