Predicted actinobacterial Zur regulons. (A), Chromosomal clusters of predicted Zur-regulated genes and their orthologues in members of the class Actinobacteria. The locations of candidate Zur-binding sites are shown by red circles. The Zur-binding sites confirmed in this study are marked with 'c'; the previously known Zur-binding sites are marked with 'k'. Homologous genes are marked by matching colour, including zinc ABC-type transporter znuABC (shades of blue), yciC for zinc allocation protein (pink), cmrA and sapD genes for surface-anchored proteins (shades of green), alcohol dehydrogenase adhA (orange), genes encoding ribosomal proteins (yellow), zur (black), znr (dark grey). (B), Consensus sequence logo for the predicted Zur-binding sites.