PROJECT SUMMARY – Overall Antibiotic resistance is a major public health concern worldwide. This CARB (Combating Antibiotic Resistant Bacteria) proposal was conceived in response to this urgent global threat. The theme of our program, “Exploiting Membrane Targets to Overcome Antibiotic Resistance,” addresses important gaps in current knowledge to facilitate translation of discoveries into strategies to combat antibiotic-resistant infections. A team of highly collaborative and productive scientists from diverse fields – chemistry, biochemistry, structural biology, and molecular genetics – has joined forces in this effort. The cell envelope, the interface between host and pathogen, is a major point of vulnerability for bacteria. Interfering with cell envelope assembly or function can inhibit bacterial growth, promote lysis, decrease resistance to host immune defenses, and increase susceptibility to other antibiotics to overcome resistance. Identifying and exploiting new ways of disrupting envelope assembly pathways to enable therapeutic discovery has been an important goal in the field. However, progress in this area has been hampered by the many challenges posed by envelope targets. Biosynthetic and regulatory processes that govern cell envelope biogenesis take place at a membrane interface and often involve proteins that contain multiple membrane-spanning segments, function in multi-protein complexes, and use complicated substrates that are not commercially available. Advancing our understanding of these cell envelope targets requires the concerted efforts of an interdisciplinary team with expertise that spans broad areas of chemistry and biology. Recent technological advances and biological discoveries, many made by the CARB project team, have transformed our understanding of cell envelope biology and opened the door to fundamentally new approaches to therapeutic targeting of this essential structure. To build on these successes, we have created a collaborative, interdisciplinary project to identify, characterize, and validate novel vulnerabilities in envelope biogenesis and maintenance pathways. The three proposed projects are not only connected by the shared focus of the investigators on cell envelope biology, their commitment to molecular mechanism as the foundation of translational research, and overlapping themes and goals, but also by synergistic collaboration among multiple investigators within as well as between each proposal. Project 1 will define the structural basis for enzymatic activity of the broadly conserved SEDS family cell wall polymerases and determine how SEDS proteins function within large macromolecular complexes during growth and division. Project 2 will focus on identifying and exploiting vulnerabilities in the Gram-positive cell envelope. Project 3 will focus on characterizing and exploiting vulnerabilities in the Gram-negative cell envelope. A streamlined administrative core will coordinate activities to maximize synergies, data sharing, and use of all program assets while providing responsible fiscal oversight.

PROJECT NARRATIVE – Overall Antibiotic resistance is one of the foremost public health concerns worldwide. This program to combat antibiotic resistance, which has as its goal to develop new approaches to treat antibiotic resistant infections by targeting the bacterial cell envelope, was specifically designed to be responsive to this global threat. A highly productive multidisciplinary team will function collaboratively to capitalize on the many advances it has already made to enable fundamentally new approaches that target this essential structure.