The rapid emergence of difficult-to-treat multidrug-resistant pathogens, combined with the scarcity of antibiotics possessing novel mechanisms, poses a significant threat to global public health. Here, we integrate the synthetic-bioinformatic natural product approach with peptide optimization to unveil the antibiotic-producing potential of Paenibacillaceae bacteria. Our culture-independent approach led to the discovery of paenimicin, a novel 11-mer depsi-lipopeptide featuring an unprecedented dual-binding mechanism. By sequestering the phosphate and hydroxyl groups of lipid A in Gram-negative bacteria, as well as the phosphate groups of teichoic acids in Gram-positive bacteria, paenimicin exhibits potent and broad-spectrum efficacy against MDR pathogens in vitro and in vivo models. Paenimicin demonstrates no detectable resistance, favorable pharmacokinetics and low nephrotoxicity, positioning it as a promising candidate for treating severe and urgent MDR infections.