Extended Data Fig. 5: Differences in σ^A–Fdx contacts between Cdiff and Mtb and σ^A sequence alignment.

a, Conserved regions of Cdiff σ^A compared to Mtb σ^A and E. coli σ⁷⁰. Mtb σ^A has a much shorter σ^A NCR than E. coli σ⁷⁰, but the residues in the short Mtb NCR that contact RbpA are not present in either Cdiff or E. coli²⁰. Mtb RbpA contacts Fdx whereas Cdiff σ^A makes more contacts to Fdx than does Mtb σ^A. Black arrows indicate RpbA- σ^A contacts whereas colored arrows indicate Fdx contacts to σ^A and RpbA, which includes one shared contact between Mtb and Cdiff σ^A (red arrow). b, Amino acid-sequence alignment of σ^A for diverse representatives of bacteria species. Identical residues are highlighted in yellow. Gaps are indicated by dashed lines. Conserved σ regions are labeled underneath the alignment. Colored boxes indicate contacts to Fdx: blue, unique to Cdiff; red, shared between Cdiff and Mtb. The three letter species code is as follows: Cdf, Clostridioides difficile; Bsu, Bacillus subtilis; Bun, Bacteroides uniformis; Eco, E. coli; Mtb, Mycobacterium tuberculosis.