Fig. 5: H-wHTH motif sequence alignment of eight selected Rrf2 family members.

Numbered α-helices (H) and labeled wing β-strands are shown on top for ScNsrR; residues conserved in at least four sequences are indicated with capitals and given in bold when they are invariant. Percentages of sequence identity with ScNsrR and Protein Data Bank codes for the structures used here are given in the %ID and pdbc columns, respectively. Residues with H-bond or salt bridge distances ≤ 3.3 Å to phosphate groups in the ScNsrR/hmpA1, SvRsrR/rsrR and EcIscR/hyA structures are highlighted in orange and those that form H-bonds to nucleobases are depicted in turquoise; additional residues within 3.8 Å of the bound DNA fragments are highlighted in gray and those that are different from ScNsrR are shown in red. Cluster binding residues in ScNsrR and SvRsrR and the oxidation-sensitive cysteine of SaCymR are highlighted in purple. Abbreviations for different bacteria are defined in the text. Tp, Sa, and Bs are Gram-positive bacteria, all the others are Gram-negative.