1. Microbiology and Infectious Disease

Maturing Mycobacterium smegmatis peptidoglycan requires non-canonical crosslinks to maintain shape

  1. Catherine Baranowski
  2. Michael A Welsh
  3. Lok-To Sham
  4. Haig A Eskandarian
  5. Hoong C Lim
  6. Karen J Kieser
  7. Jeffrey C Wagner
  8. John McKinney
  9. Georg E Fantner
  10. Thomas R Ioerger
  11. Suzanne Walker
  12. Thomas G Bernhardt
  13. Eric J Rubin  Is a corresponding author
  14. E Hesper Rego  Is a corresponding author
  1. Harvard TH Chan School of Public Health, United States
  2. Harvard Medical School, United States
  3. Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
  4. Texas A&M University, United States
  5. Yale School of Medicine, United States
https://doi.org/10.7554/eLife.37516
Share this article
Cite this article
  1. Catherine Baranowski
  2. Michael A Welsh
  3. Lok-To Sham
  4. Haig A Eskandarian
  5. Hoong C Lim
  6. Karen J Kieser
  7. Jeffrey C Wagner
  8. John McKinney
  9. Georg E Fantner
  10. Thomas R Ioerger
  11. Suzanne Walker
  12. Thomas G Bernhardt
  13. Eric J Rubin
  14. E Hesper Rego
(2018)
Maturing Mycobacterium smegmatis peptidoglycan requires non-canonical crosslinks to maintain shape
eLife 7:e37516.
https://doi.org/10.7554/eLife.37516
  2. Download BibTeX
  3. Download .RIS

Abstract

In most well studied rod-shaped bacteria, peptidoglycan is primarily crosslinked by penicillin-binding proteins (PBPs). However, in mycobacteria, crosslinks formed by L,D-transpeptidases (LDTs) are highly abundant. To elucidate the role of these unusual crosslinks, we characterized Mycobacterium smegmatis cells lacking all LDTs. We find that crosslinks generate by LDTs are required for rod shape maintenance specifically at sites of aging cell wall, a byproduct of polar elongation. Asymmetric polar growth leads to a non-uniform distribution of these two types of crosslinks in a single cell. Consequently, in the absence of LDT-mediated crosslinks, PBP-catalyzed crosslinks become more important. Because of this, Mycobacterium tuberculosis (Mtb) is more rapidly killed using a combination of drugs capable of PBP- and LDT- inhibition. Thus, knowledge about the spatial and genetic relationship between drug targets can be exploited to more effectively treat this pathogen.

Data availability

Sequencing data were deposited into NCBI's Sequence Read Archive (SRA) under SRA study- SRP141343 https://www.ncbi.nlm.nih.gov/Traces/study/?acc=SRP141343

The following data sets were generated

Article and author information

Author details

  1. Catherine Baranowski

    Department of Immunology and Infectious Disease, Harvard TH Chan School of Public Health, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0407-8609

  2. Michael A Welsh

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8268-6285

  3. Lok-To Sham

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  4. Haig A Eskandarian

    School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0610-0550

  5. Hoong C Lim

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  6. Karen J Kieser

    Department of Immunology and Infectious Disease, Harvard TH Chan School of Public Health, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  7. Jeffrey C Wagner

    Department of Immunology and Infectious Disease, Harvard TH Chan School of Public Health, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  8. John McKinney

    School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    Competing interests
    The authors declare that no competing interests exist.

  9. Georg E Fantner

    School of Engineering, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    Competing interests
    The authors declare that no competing interests exist.

  10. Thomas R Ioerger

    Department of Computer Science and Engineering, Texas A&M University, College Station, United States
    Competing interests
    The authors declare that no competing interests exist.

  11. Suzanne Walker

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  12. Thomas G Bernhardt

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3566-7756

  13. Eric J Rubin

    Department of Immunology and Infectious Disease, Harvard TH Chan School of Public Health, Boston, United States
    For correspondence
    erubin@hsph.harvard.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5120-962X

  14. E Hesper Rego

    Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, United States
    For correspondence
    hesper.rego@yale.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2973-8354

Funding

National Institutes of Health (U19 AI107774)

  • Thomas R Ioerger
  • Eric J Rubin

National Institutes of Health (R01 GM76710)

  • Suzanne Walker

National Institutes of Health (R01AI083365)

  • Thomas G Bernhardt

National Institutes of Health (F32GM123579)

  • Michael A Welsh

Swiss National Science Foundation (205321_134786)

  • Georg E Fantner

Innovative Medicines Initiative (115337)

  • John McKinney

EU-FP7/Eurostars (E!8213)

  • Georg E Fantner

European Molecular Biology Organization (750-2016)

  • Haig A Eskandarian

National Science Foundation (DGE0946799)

  • Karen J Kieser

National Institutes of Health (U19AI109764)

  • Thomas G Bernhardt

Swiss National Science Foundation (205320_152675)

  • Georg E Fantner

Burroughs Wellcome Fund (Career Award at the Scientific Interface)

  • E Hesper Rego

American Heart Association (14POST18480014)

  • Lok-To Sham

Simons Foundation (Fellow of the Life Sciences Research Foundation Award)

  • Hoong C Lim

Swiss National Science Foundation (310030_156945)

  • John McKinney

European Union (FP7/2007-2013/ERC Grant agreement No. 307338 (NaMic))

  • Georg E Fantner

European Molecular Biology Organization (191-2014)

  • Haig A Eskandarian

National Science Foundation (DGE1144152)

  • Karen J Kieser

National Institutes of Health (F32AI104287)

  • E Hesper Rego

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2018, Baranowski et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 6,012
    views
  • 862
    downloads
  • 116
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Catherine Baranowski
  2. Michael A Welsh
  3. Lok-To Sham
  4. Haig A Eskandarian
  5. Hoong C Lim
  6. Karen J Kieser
  7. Jeffrey C Wagner
  8. John McKinney
  9. Georg E Fantner
  10. Thomas R Ioerger
  11. Suzanne Walker
  12. Thomas G Bernhardt
  13. Eric J Rubin
  14. E Hesper Rego
(2018)
Maturing Mycobacterium smegmatis peptidoglycan requires non-canonical crosslinks to maintain shape
eLife 7:e37516.
https://doi.org/10.7554/eLife.37516

Share this article

https://doi.org/10.7554/eLife.37516

Categories and tags

Further reading

    1. Biochemistry and Chemical Biology
    2. Microbiology and Infectious Disease

    Peptidoglycan precursor synthesis along the sidewall of pole-growing mycobacteria

    Alam García-Heredia, Amol Arunrao Pohane ... M Sloan Siegrist
    Research Article Updated

    Rod-shaped mycobacteria expand from their poles, yet d-amino acid probes label cell wall peptidoglycan in this genus at both the poles and sidewall. We sought to clarify the metabolic fates of these probes. Monopeptide incorporation was decreased by antibiotics that block peptidoglycan synthesis or l,d-transpeptidation and in an l,d-transpeptidase mutant. Dipeptides complemented defects in d-alanine synthesis or ligation and were present in lipid-linked peptidoglycan precursors. Characterizing probe uptake pathways allowed us to localize peptidoglycan metabolism with precision: monopeptide-marked l,d-transpeptidase remodeling and dipeptide-marked synthesis were coincident with mycomembrane metabolism at the poles, septum and sidewall. Fluorescent pencillin-marked d,d-transpeptidation around the cell perimeter further suggested that the mycobacterial sidewall is a site of cell wall assembly. While polar peptidoglycan synthesis was associated with cell elongation, sidewall synthesis responded to cell wall damage. Peptidoglycan editing along the sidewall may support cell wall robustness in pole-growing mycobacteria.

    1. Epidemiology and Global Health
    2. Microbiology and Infectious Disease

    Tuberculosis: Breaking down walls

    Moagi Tube Shaku, Bavesh Davandra Kana
    Insight

    A better understanding of the mechanisms underpinning the growth of mycobacteria could help identify targets for new antibiotics.

    1. Microbiology and Infectious Disease

    Viruses: How herpes is assembled

    Dawid S Zyla
    Insight

    A combination of imaging techniques reveals how herpes simplex virus type 1 assembles within infected cells, highlighting the roles of essential viral proteins in viral assembly and exit.