Crystal structures of the transpeptidase domain of the Mycobacterium tuberculosis penicillin‐binding protein PonA1 reveal potential mechanisms of antibiotic resistance
- Department of Biochemistry and Molecular Genetics Feinberg School of Medicine Northwestern University Chicago IL USA, Midwest Center for Structural Genomics (MCSG) Biosciences Division Argonne National Laboratory Argonne, IL USA, Center for Structural Genomics of Infectious Diseases (CSGID) Feinberg School of Medicine Northwestern University Chicago, IL USA
- Department of Immunology and Infectious Disease Harvard T.H. Chan School of Public Health Boston MA USA
- Midwest Center for Structural Genomics (MCSG) Biosciences Division Argonne National Laboratory Argonne, IL USA, High Throughput Analysis Laboratory and Department of Molecular Biosciences Northwestern University Evanston IL USA
- Life Science Collaborative Access Team Synchrotron Research Center Northwestern University Evanston IL USA
- Department of Immunology and Infectious Disease Harvard T.H. Chan School of Public Health Boston MA USA, Department of Microbiology and Immunobiology Harvard Medical School Boston MA USA
Mycobacterium tuberculosis is a human respiratory pathogen that causes the deadly disease tuberculosis. The rapid global spread of antibiotic‐resistant M. tuberculosis makes tuberculosis infections difficult to treat. To overcome this problem new effective antimicrobial strategies are urgently needed. One promising target for new therapeutic approaches is PonA1, a class A penicillin‐binding protein, which is required for maintaining physiological cell wall synthesis and cell shape during growth in mycobacteria. Here, crystal structures of the transpeptidase domain, the enzymatic domain responsible for penicillin binding, of PonA1 from M. tuberculosis in the inhibitor‐free form and in complex with penicillin V are reported. We used site‐directed mutagenesis, antibiotic profiling experiments, and fluorescence thermal shift assays to measure PonA1's sensitivity to different classes of β‐lactams. Structural comparison of the PonA1 apo‐form and the antibiotic‐bound form shows that binding of penicillin V induces conformational changes in the position of the loop β4′‐α3 surrounding the penicillin‐binding site. We have also found that binding of different antibiotics including penicillin V positively impacts protein stability, while other tested β‐lactams such as clavulanate or meropenem resulted in destabilization of PonA1. Our antibiotic profiling experiments indicate that the transpeptidase activity of PonA1 in both M. tuberculosis and M. smegmatis mediates tolerance to specific cell wall‐targeting antibiotics, particularly to penicillin V and meropenem. Because M. tuberculosis is an important human pathogen, these structural data provide a template to design novel transpeptidase inhibitors to treat tuberculosis infections. Database Structural data are available in the PDB database under the accession numbers 5CRF and 5CXW .
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC02-06CH11357; [085P1000817]; NIH [GM074942]; NSF [DGE1144152; DGE0946799; MCB 1024945; HHS [HHSN272200700058C; HHSN2722012 00026C]
- OSTI ID:
- 1254659
- Alternate ID(s):
- OSTI ID: 1254660; OSTI ID: 1625876
- Journal Information:
- Federation of European Biochemical Societies (FEBS) Journal, Journal Name: Federation of European Biochemical Societies (FEBS) Journal Vol. 283 Journal Issue: 12; ISSN 1742-464X
- Publisher:
- Wiley-BlackwellCopyright Statement
- Country of Publication:
- United Kingdom
- Language:
- English
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