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Lookup NU author(s): Dr Curtis Cottam, Dr Kieran BowranORCiD, Dr Arnaud Basle, Dr Kesha JostsORCiD, Dr James ConnollyORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© The Author(s) 2025.Attaching and effacing pathogens overcome colonisation resistance by competing with metabolically similar organisms for limited resources. Enterohaemorrhagic E. coli (EHEC) utilises the pathogenicity island-encoded Accessory ʟ-arabinose Uptake (Aau) transporter to effectively colonise the mouse gut, hypothesised to be achieved via an enhanced capacity to scavenge ʟ-arabinose. Aau is regulated exclusively in response to ʟ-arabinose, but it is unclear how this system specifically benefits EHEC in vivo. Here, we show that Aau displays a > 200-fold higher affinity for the monosaccharide D-ribulose, over ʟ-arabinose. EHEC cannot grow on D-ribulose as a sole carbon source and this sugar does not trigger aau transcription. However, Aau effectively transports D-ribulose into the cell only in the presence of ʟ-arabinose, where it feeds into the pentose phosphate pathway, after phosphorylation by the ʟ-ribulokinase AraB, thus providing EHEC a significant fitness advantage. EHEC has therefore evolved a mechanism of hijacking the canonical ʟ-arabinose utilisation machinery to promote D-ribulose utilisation in vivo. Furthermore, Citrobacter rodentium encodes an analogous system that exclusively transports D-ribulose and metabolises it via a dedicated D-ribulokinase. These unique mechanisms of D-ribulose utilisation suggest that convergent evolution has driven the ability of distinct pathogenic species to exploit this nutrient during invasion of the gut niche.
Author(s): Cottam C, Bowran K, White RT, Basle A, Josts I, Connolly JPR
Publication type: Article
Publication status: Published
Journal: Nature Communications
Year: 2025
Volume: 16
Issue: 1
Online publication date: 29/07/2025
Acceptance date: 23/07/2025
Date deposited: 12/08/2025
ISSN (electronic): 2041-1723
Publisher: Nature Research
URL: https://doi.org/10.1038/s41467-025-62476-5
DOI: 10.1038/s41467-025-62476-5
Data Access Statement: The X-ray crystal structure of AauA has been deposited to the Protein Data Bank under the accession ID 9I1M. Source data for Figs. 1–6 and Supplementary Figs. 1–6 and 10–12 are provided with this paper as a Source Data file. Publicly available genome sequences used in Fig. 6 and Supplementary Fig. 11 were obtained from the NCBI Sequence Read Archive and the Integrated Microbial Genomes and Microbiomes database, with the corresponding metadata and accession numbers provided in the Source Data file. Source data are provided with this paper.
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