uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Molecular mechanism of viomycin inhibition of peptide elongation in bacteria
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology.
2016 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 4, 978-983 p.Article in journal (Refereed) Published
Resource type
Text
Abstract [en]

Viomycin is a tuberactinomycin antibiotic essential for treating multi-drug-resistant tuberculosis. It inhibits bacterial protein synthesis by blocking elongation factor G (EF-G) catalyzed translocation of messenger RNA on the ribosome. Here we have clarified the molecular aspects of viomycin inhibition of the elongating ribosome using pre-steady-state kinetics. We found that the probability of ribosome inhibition by viomycin depends on competition between viomycin and EF-G for binding to the pretranslocation ribosome, and that stable viomycin binding requires an A-site bound tRNA. Once bound, viomycin stalls the ribosome in a pretranslocation state for a minimum of similar to 45 s. This stalling time increases linearly with viomycin concentration. Viomycin inhibition also promotes futile cycles of GTP hydrolysis by EF-G. Finally, we have constructed a kinetic model for viomycin inhibition of EF-G catalyzed translocation, allowing for testable predictions of tuberactinomycin action in vivo and facilitating in-depth understanding of resistance development against this important class of antibiotics.

Place, publisher, year, edition, pages
2016. Vol. 113, no 4, 978-983 p.
Keyword [en]
protein synthesis, viomycin, ribosome, antibiotics, tuberculosis
National Category
Microbiology in the medical area
Identifiers
URN: urn:nbn:se:uu:diva-277786DOI: 10.1073/pnas.1517541113ISI: 000368617900047PubMedID: 26755601OAI: oai:DiVA.org:uu-277786DiVA: diva2:905799
Available from: 2016-02-23 Created: 2016-02-23 Last updated: 2017-11-30Bibliographically approved
In thesis
1. A tale of two antibiotics: Fusidic acid and Viomycin
Open this publication in new window or tab >>A tale of two antibiotics: Fusidic acid and Viomycin
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Antibiotics that target the bacterial ribosome make up about half of all clinically used antibiotics. We have studied two ribosome targeting drugs: Fusidic acid and Viomycin. Fusidic acid inhibits bacterial protein synthesis by binding to elongation factor G (EF-G) on the ribosome, thereby inhibiting translocation of the bacterial ribosome. Viomycin binds directly to the ribosome and inhibits both the fidelity of mRNA decoding and translocation. We found that the mechanisms of inhibition of these two antibiotics were unexpectedly complex. Fusidic acid can bind to EF-G on the ribosome during three separate stages of translocation. Binding of the drug to the first and most sensitive state does not lead to stalling of the ribosome. Rather the ribosome continues unhindered to a downstream state where it stalls for around 8 seconds. Dissociation of fusidic acid from this state allows the ribosome to continue translocating but it soon reaches yet another fusidic acid sensitive state where it can be stalled again, this time for 6 seconds. Viomycin inhibits translocation by binding to the pre-translocation ribosome in competition with EF-G. If viomycin binds before EF-G it stalls the ribosome for 44 seconds, much longer than a normal elongation cycle. Both viomycin and fusidic acid probably cause long queues of ribosomes to build up on the mRNA when they bind. Viomycin inhibits translational fidelity by binding to the ribosome during initial selection. We found that the concentration of viomycin required to bind to the ribosome with a given probability during decoding is proportional to the accuracy of the codon∙anticodon pair being decoded. This demonstrated that long standing models about ribosomal accuracy cannot be correct. Finally, we demonstrated that a common viomycin resistance mutation increases the drug binding rate and decreases its dissociation rate. Our results demonstrate that ribosome targeting drugs have unexpectedly complex mechanisms of action. Both fusidic acid and viomycin preferentially bind to conformations of the ribosome other than those that they stabilize. This suggests that determining the structures of stable drug-bound states may not give sufficient information for drug design.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. 64 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1399
Keyword
Protein Synthesis, Antibiotics, Fusidic acid, Viomycin, Translocation, Accuracy
National Category
Biochemistry and Molecular Biology
Research subject
Molecular Biotechnology
Identifiers
urn:nbn:se:uu:diva-300479 (URN)978-91-554-9644-9 (ISBN)
External cooperation:
Public defence
2016-09-23, B41 BMC, Husargatan 3, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2016-09-01 Created: 2016-08-09 Last updated: 2016-09-05

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Authority records BETA

Holm, MikaelBorg, AnneliEhrenberg, MånsSanyal, Suparna

Search in DiVA

By author/editor
Holm, MikaelBorg, AnneliEhrenberg, MånsSanyal, Suparna
By organisation
Structure and Molecular Biology
In the same journal
Proceedings of the National Academy of Sciences of the United States of America
Microbiology in the medical area

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 910 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf