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.

The first crystal structure of NAD-dependent 3-dehydro-2-deoxy-D-gluconate dehydrogenase from Thermus thermophilus HB8

The crystal structure of 3-dehydro-3-deoxy-D-gluconate 5-dehydrogenase from T. thermophilus HB8 has been determined in the apo form, as well as in complexes with the cofactor and with citrate, by X-ray diffraction methods. The citrate molecule and the cofactor have been identified deep in the cleft formed between the interface of two adjacent subunits. These structures provide insights into the substrate recognition and catalytic machinery of 3-dehydro-3-deoxy-D-gluconate 5-dehydrogenase.