This competing renewal of GM076710 involves research on bacterial cell wall biosynthesis, an essential and highly conserved pathway that is a well-validated target for antibiotics, including the beta lactams and the glycopeptides (e.g., vancomycin), two of the most important classes of clinically used antibiotics in history. Unfortunately, resistance to these and other clinically used classes of antibiotics has become a major problem and it is critical to develop new approaches to overcome resistant infections. Studies to understand known as well as new possible targets, in conjunction with methods to evaluate inhibition of these targets, may ultimately lead to new antibiotics. Hence, the overall goal of this renewal is to develop tools and methods to study the final steps of peptidoglycan assembly and apply them to characterize biosynthetic enzymes as well as cell wall inhibitors. These final steps of PG assembly are notoriously difficult to study because the chemical transformations involve large, complex molecules and some of the enzymes are integral membrane proteins. This renewal combines synthetic and enzymatic approaches to obtain substrates with enzymology, bacterial genetics, and cell biology to probe enzyme mechanism and inhibition both in vitro and in cells. There are four specific aims: 1) to develop tools to quantify pool levels of key intermediates in PG biosynthesis in order to verify inhibition of PG biosynthetic enzymes and determine mechanism of action of cell wall targeting antibiotics; 2) to develop substrates and assays to study bacterial transpeptidases and apply them to characterize PBP2a, the transpeptidase responsible for beta lactam resistance in Staphylococcus aureus, with the longterm aim of exploiting this knowledge to develop strategies to overcome PBP2a-mediated resistance; 3) to develop methods to study cell wall tailoring enzymes that attach teichoic acids and other glycopolymers to PG because these enzymes are possible targets for antibiotics; and 4) to develop methods to probe translocation of Lipid II and its inhibition in both Gram negative and Gram positive organisms because the Lipid II flippases are also possible targets for antibiotics.

Public Health Relevance

Antibiotic resistant microorganisms pose a major threat to human health. This grant describes studies to counteract that threat by developing tools and methods to characterize enzymes involved in bacterial cell wall biosynthesis. This pathway is a major target for antibiotics and better characterization of important enzymes in the pathway could lead to new antibiotics to treat resistant infections.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Synthetic and Biological Chemistry B Study Section (SBCB)
Program Officer
Marino, Pamela
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Harvard Medical School
Schools of Medicine
United States
Zip Code
Matano, Leigh M; Morris, Heidi G; Hesser, Anthony R et al. (2017) Antibiotic That Inhibits the ATPase Activity of an ATP-Binding Cassette Transporter by Binding to a Remote Extracellular Site. J Am Chem Soc 139:10597-10600
Qiao, Yuan; Srisuknimit, Veerasak; Rubino, Frederick et al. (2017) Lipid II overproduction allows direct assay of transpeptidase inhibition by ?-lactams. Nat Chem Biol 13:793-798
Srisuknimit, Veerasak; Qiao, Yuan; Schaefer, Kaitlin et al. (2017) Peptidoglycan Cross-Linking Preferences of Staphylococcus aureus Penicillin-Binding Proteins Have Implications for Treating MRSA Infections. J Am Chem Soc 139:9791-9794
Welsh, Michael A; Taguchi, Atsushi; Schaefer, Kaitlin et al. (2017) Identification of a Functionally Unique Family of Penicillin-Binding Proteins. J Am Chem Soc 139:17727-17730
Schaefer, Kaitlin; Matano, Leigh M; Qiao, Yuan et al. (2017) In vitro reconstitution demonstrates the cell wall ligase activity of LCP proteins. Nat Chem Biol 13:396-401
Meeske, Alexander J; Riley, Eammon P; Robins, William P et al. (2016) SEDS proteins are a widespread family of bacterial cell wall polymerases. Nature 537:634-638
Lee, Wonsik; Schaefer, Kaitlin; Qiao, Yuan et al. (2016) The Mechanism of Action of Lysobactin. J Am Chem Soc 138:100-3
Markovski, Monica; Bohrhunter, Jessica L; Lupoli, Tania J et al. (2016) Cofactor bypass variants reveal a conformational control mechanism governing cell wall polymerase activity. Proc Natl Acad Sci U S A 113:4788-93
Goodreid, Jordan D; Janetzko, John; Santa Maria Jr, John P et al. (2016) Development and Characterization of Potent Cyclic Acyldepsipeptide Analogues with Increased Antimicrobial Activity. J Med Chem 59:624-46
Schirner, Kathrin; Eun, Ye-Jin; Dion, Mike et al. (2015) Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB. Nat Chem Biol 11:38-45

Showing the most recent 10 out of 49 publications