Integrated omics-based mechanistical insights into a membrane-targeting antibacterial

Here, we investigated HSI#6, a small-molecule antibacterial previously identified as a SecA activator, using integrated omics and functional assays. HSI#6 exhibits broad-spectrum bacteriostatic activity and acts through a dual-phase mechanism: transient activation of SecA-dependent secretion followed by membrane perturbation and global stress reprogramming.

Time-resolved transcriptomics and proteomics revealed early activation of envelope stress regulons (Cpx, Rcs, Pho), efflux systems, and oxidative stress pathways, followed by suppression of ribosome biogenesis and central metabolism. Comparative analysis and biomarker-based principle component analysis (PCA) positioned HSI#6 within the envelope stress mechanistic space, closely aligned with membrane-active antibiotics yet displaying a distinct signature.