Figure 5.

Structure of the E. coli MqsA-DNA complex. Tertiary structure of the E. coli-encoded MqsA dimer in complex with its operator DNA (PDB accession: 3O9X). The monomers of the MqsA dimer are colored either in green or in blue with their N- and C-termini indicated in their respective colors; zinc ions are shown as gray spheres; the mqsRA operator DNA is depicted in orange. For clarity, the MqsA amino acid residues that are crucial for interaction with operator DNA (Phe-22, Arg-23, Lys-58, and Arg-61) are shown for only one of the monomers as are the cysteine residues (Cys-3, Cys-6, Cys-37, and Cys-40) involved in coordination with the zinc ion (Brown et al., 2011).