Structural insights into the molecular mechanism of Escherichia coli SdiA, a quorum-sensing receptor

Crystal structures of the full-length E. coli quorum-sensing receptor SdiA reveal that it forms a symmetrical dimer and exhibits broad ligand-binding selectivity. The ligand binding increases the stability of SdiA but does not modulate its DNA-binding ability. The DNA-binding activity of SdiA can be regulated through the formation of an intersubunit disulfide bond.