Journal: mBio

Article Title: The iron-regulated small regulatory RNA IsrR modulates expression of genes utilized for dioxygen metabolism and heme synthesis in Staphylococcus aureus

doi: 10.1128/mbio.01415-25

Figure Lengend Snippet: IsrR represses dioxygen respiration. ( A ) Dioxygen consumption rate (OCR) was determined in the wild type (WT; JMB1100), Δ isrR (JMB11292), Δ fur::tet (JMB10842), Δ isrR Δ fur::tet (JMB11293), sucA::Tn (JMB14125), Δ acnA::tet (JMB8563), and hemB::Tn (JMB4536) strains cultured in TSB after 34 min incubation at 37°C. ( B ) Extracellular acidification rates of strains in panel A after 90 min of incubation at 37°C. ( C ) Membrane potentials of the WT, Δ isrR, Δ fur, Δ isrR Δ fur::tet, Δ acnA::tet, and hemB strains were measured using the fluorescent dye 3’3’-diethyloxacarbocyanine iodide (DiOC 2 ) with and without membrane decoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP). ( D ) Relative fluorescence of the WT, Δ isrR, Δ fur, and Δ isrR Δ fur strains containing the pOS_P lgt _ cydA_gfp translational reporter after culture in TSB-Cm media. ( E ) An electrophoretic mobility shift assay (EMSA) using 5’ radiolabeled IsrR (*) incubated with increasing concentrations (0, 50, 100, 250, and 500 nM) of cydA (−42 to +781) and cydB (−172 to +725) transcripts. Data in panels A to D are reported as the average, and error bars indicate standard deviation (A and B, n = 8; C, n = 4; D, n = 3). An ordinary one-way ANOVA (A, B, and D) or two-way ANOVA (C) , followed by Tukey’s multiple comparisons test, was used to analyze the data. * P -value < 0.05, ** P -value < 0.01, **** P -value < 0.0001.

Article Snippet: Unless otherwise stated, all S. aureus strains were grown at 37°C in tryptic soy broth (TSB) (MP Biomedicals).

Techniques: Cell Culture, Incubation, Membrane, Fluorescence, Electrophoretic Mobility Shift Assay, Standard Deviation