Fig. 2.

Halalkalibacterium halodurans Δole-oapA strain spontaneously acquires suppressor mutations that restore robust growth on EMM. A) Depiction of the distribution of mutations (47 in total) observed across 31 unique H. halodurans Δole-oapA EMM suppressor isolates. Silent mutations were excluded. The Mn²⁺ riboswitch is located immediately upstream of the ykoY ORF. The protein products encoded by bmrC and bmrD form a heterodimer. B) Growth assays in liquid EMM with H. halodurans WT, Δole-oapA, and Δole-oapA carrying various suppressor mutations as indicated. Biological replicates (n = 3) were performed on separate days and are indicated as Rep 1 through Rep 3. Bars indicate average OD₆₀₀ values from biological replicates wherein each replicate was comprised of three technical replicates. Error bars indicate standard deviation. C) Representative growth assay on EMM agar with various suppressor isolates after 4 days of growth at 37 °C. Agar spot assays were performed with at least three independent biological replicates and each biological replicate was spotted on EMM agar three separate times, wherein all gave results similar to those depicted.