Figure 3. The structural alignments between mercury(II)-bound Tn501 MerR and Bacillus MerR.

(a) Tertiary structural superimpositions and (b) Quaternary structural superimpositions of the Hg²⁺-MerR complex between Tn501 MerR (PDB code 5CRL) and Bacillus MerR (PDB code 4UA1). The structures of MerR proteins are shown as cartoon representations, with Tn501 MerR in green and Bacillus MerR in slate. (c) A stereodrawing of the metal-binding region in Tn501 MerR. (d) A stereodrawing of the metal-binding region in Bacillus MerR. In (c,d), the residues in the metal-binding region are shown as stick representations. The interactions within this region are shown as black dotted lines.