The structure of NMB1585, a MarR-family regulator from Neisseria meningitidis

The structure of the MarR-family transcription factor NMB1585 from Neisseria meningitidis has been solved using data extending to a resolution of 2.1 angstrom. Overall, the dimeric structure resembles those of other MarR proteins, with each subunit comprising a winged helix-turn-helix (wHtH) domain connected to an alpha-helical dimerization domain. The spacing of the recognition helices of the wHtH domain indicates that NMB1585 is pre-configured for DNA binding, with a putative inducer pocket that is largely occluded by the side chains of two aromatic residues (Tyr29 and Trp53). NMB1585 was shown to bind to its own promoter region in a gel-shift assay, indicating that the protein acts as an auto-repressor.