Frontispiece: C‐terminal Cysteines of CueR Act as Auxiliary Metal Site Ligands upon HgII Binding—A Mechanism To Prevent Transcriptional Activation by Divalent Metal Ions?

The transcriptional regulator CueR controls the intracellular concentration of CuI. HgII exhibits strong binding to the bis‐thiolate functional metal binding site but does not induce transcription. Here it has been shown that HgS3 structure appears under sub‐equimolar HgII‐concentrations at pH=8.0, suggesting that the conserved C‐terminal CCHH motif provides an auxiliary ligand for divalent metal ions, possibly preventing the transcription. For more information, see the Communication by A. Janscó et al. on page 15030 ff.