Preacinetobactin not acinetobactin is essential for iron uptake by the BauA transporter of the pathogen Acinetobacter baumannii
- Wellcome Trust Centre of Human Genomics, United Kingdom
- University of Cagliari, Italy
- The University of St Andrews, United Kingdom
- Jacobs University, Germany
Abstract
New strategies are urgently required to develop antibiotics. The siderophore uptake system has attracted considerable attention but rational design of siderophore antibiotic conjugates requires knowledge of recognition by the cognate outer membrane transporter. Acinetobacter baumannii is a serious pathogen, which utilizes (pre)acinetobactin to scavenge iron from the host. We report the structure of the (pre)acinetobactin transporter BauA bound to the siderophore, identifying the structural determinants of recognition. Detailed biophysical analysis confirms that BauA recognises preacinetobactin. We show that acinetobactin is not recognised by the protein thus preacinetobactin is essential for iron uptake. The structure shows and NMR confirms that under physiological conditions a molecule of acinetobactin will bind to two free coordination sites on the iron preacinetobactin complex. The ability to recognise a heterotrimeric iron preacinetobactin acinetobactin complex may rationalize contradictory reports in the literature. These results open new avenues for the design of novel antibiotic conjugates (trojan horse) antibiotics.
Data availability
Diffraction data have been deposited in PDB under the accession codes 6H7F, 6H7V, 6HCP.
Article and author information
Author details
Funding
European Union (115525)
- Lucile Moynie
- Ilaria Serra
- Mariano A Scorciapino
- Malcolm GP Page
- Matteo Ceccarelli
- James H Naismith
Wellcome (100209/Z/12/Z)
- Lucile Moynie
- James H Naismith
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2018, Moynie 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.
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Preacinetobactin not acinetobactin is essential for iron uptake by the BauA transporter of the pathogen Acinetobacter baumannii
eLife 7:e42270.
https://doi.org/10.7554/eLife.42270
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