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.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM076710-10
Application #
9199238
Study Section
Synthetic and Biological Chemistry B Study Section (SBCB)
Program Officer
Marino, Pamela
Project Start
2005-12-01
Project End
2019-11-30
Budget Start
2016-12-01
Budget End
2017-11-30
Support Year
10
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Harvard Medical School
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
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
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
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
Qiao, Yuan; Lebar, Matthew D; Schirner, Kathrin et al. (2014) Detection of lipid-linked peptidoglycan precursors by exploiting an unexpected transpeptidase reaction. J Am Chem Soc 136:14678-81
Garg, Neha; Oman, Trent J; Andrew Wang, Tsung-Shing et al. (2014) Mode of action and structure-activity relationship studies of geobacillin I. J Antibiot (Tokyo) 67:133-6
Sham, Lok-To; Butler, Emily K; Lebar, Matthew D et al. (2014) Bacterial cell wall. MurJ is the flippase of lipid-linked precursors for peptidoglycan biogenesis. Science 345:220-2
Lupoli, Tania J; Lebar, Matthew D; Markovski, Monica et al. (2014) Lipoprotein activators stimulate Escherichia coli penicillin-binding proteins by different mechanisms. J Am Chem Soc 136:52-5
Rebets, Yuriy; Lupoli, Tania; Qiao, Yuan et al. (2014) Moenomycin resistance mutations in Staphylococcus aureus reduce peptidoglycan chain length and cause aberrant cell division. ACS Chem Biol 9:459-67

Showing the most recent 10 out of 44 publications