Crystal structure of the full?length LysR?type transcription regulator CbnR in complex with promoter DNA

LysR-type transcription regulators (LTTRs) comprise one of the largest families transcriptional in bacteria. They are typically homo-tetrameric proteins and interact with promoter DNA ~ 50–60 bp. Earlier biochemical studies have suggested that LTTR binding to bends and, upon inducer binding, bend angle is reduced through a quaternary structure change tetrameric LTTR, leading activation transcription. To date, crystal structures full-length LTTRs, DNA-binding domains (DBD) their target DNAs, regulatory without molecules been reported. However, these not provided direct evidence changes LTTRs or molecular mechanism underlying changes. Here, we report first CbnR, complex its DNA. The showed that, absence bound molecules, four DBDs CbnR DNA, bending by 70°. Structural comparison between DNA-free DNA-bound forms demonstrates required for region-binding arises from relative orientation three each subunit. caused also discussed based on present structure, affinity analysis earlier mutational CbnR. Database Atomic coordinates factors Cupriavidus necator NH9 available Protein Data Bank under accession code 7D98.