Fig. 5: D-ribulokinase activity of AraB is essential for growth of EHEC on D-ribulose.

a Overlayed AlphaFold3 model of RblK (Blue) from C. rodentium with the crystal structure of AraB from the Protein Data Bank (3QDK) (Grey). b Detailed view of the binding cleft from the overlay in panel, with L-ribulose included to illustrate the key interacting residues known for AraB. The dashed lines indicate hydrogen bonds. a illustrating conservation of key residues in RblK with the known FGGY-family carbohydrate kinase, AraB. c Growth analysis of wild type EHEC (str. TUV93-0; encoding a non-functional Aau system), EHEC + pSU-aau, and ∆araBAD + pSU-aau in M9 minimal media supplemented with D-ribulose as a sole carbon source. d, Growth analysis of EHEC, EHEC + pSU-aau, and ∆araBAD + pSU-aau in M9 supplemented with ʟ-arabinose as a sole carbon source. e Growth analysis of EHEC, EHEC + pSU-aau, and ∆araBAD + pSU-aau in M9 supplemented with ʟ-arabinose and D-ribulose as carbon sources. Error bars for growth curves represent the standard deviation from three independent experiments (n = 3 biological replicates). Non-linear regression was used to fit growth models, from which growth rate constants k were extracted and compared using a two-tailed student’s t-test. f Kinase assay using purified recombinant AraB from EHEC (str. ZAP193) incubated with buffer, D-glucose or D-ribulose. Kinase activity was measured as raw luminescence units. The error bars represent the standard deviation from the mean of three independent experiments (n = 3 biological replicates). Statistical significance was determined using a two-tailed Student’s t-test; ns indicates not significant. Source data are provided as a Source Data file.