Figure 1. LhaSTA represents an iron-regulated heme transporter.

(A) Schematic diagram of the isd operon of S. lugdunensis N920143. Coding sequences, direction of transcription and Fur-binding sites are indicated. ABC membrane-transporters are shown in green. lhaS - SLUG_00900; lhaT - SLUG_00910; lhaA - SLUG_00920 (B) Iron-regulated expression of Lha: S. lugdunensis was grown overnight in TSB, TSB + 200 µM EDDHA or TSB + 200 µM EDDHA + 200 µM FeSO₄. Gene expression was quantified by qPCR. Expression was normalized to 5srRNA and to the TSB standard condition using the ΔΔCt method. Fold differences in gene expression are shown. Data represent mean and SD of four independent experiments. Statistical evaluation was performed using students unpaired t-test (lhaS: t = 7,045, df = 6; lhaA: t = 2,979, df = 6) C/D Growth curves of S. lugdunensis N920143 and isogenic mutants. The wild type (WT) S. lugdunensis N920143 strain and the indicated isogenic null mutant strains were grown in the presence of 20 µM FeSO₄ (C) or 150 nM heme (D) as a sole source of iron. 500 µl of bacterial cultures were inoculated to an OD₆₀₀ = 0,05 in 48 well plates and OD₆₀₀ was monitored every 15 min using an Epoch1 plate reader. For reasons of clarity values taken every 5 hr are displayed. Mean and SD of three experiments are shown. Statistical analysis was performed using one-way ANOVA followed by Dunett’s test for multiple comparisons. * - p<0,05, ****p<0,00001.