Download MendeleyMechanism of Activation for Transcription Factor PhoB Suggested by Different Modes of Dimerization in the Inactive and Active States.
Bachhawat, P., Swapna, G.V., Montelione, G.T., Stock, A.M.(2005) Structure 13: 1353-1363
- PubMed: 16154092
- DOI: https://doi.org/10.1016/j.str.2005.06.006
- Primary Citation of Related Structures:
1ZES - PubMed Abstract:
Response regulators (RRs), which undergo phosphorylation/dephosphorylation at aspartate residues, are highly prevalent in bacterial signal transduction. RRs typically contain an N-terminal receiver domain that regulates the activities of a C-terminal DNA binding domain in a phosphorylation-dependent manner. We present crystallography and solution NMR data for the receiver domain of Escherichia coli PhoB which show distinct 2-fold symmetric dimers in the inactive and active states. These structures, together with the previously determined structure of the C-terminal domain of PhoB bound to DNA, define the conformation of the active transcription factor and provide a model for the mechanism of activation in the OmpR/PhoB subfamily, the largest group of RRs. In the active state, the receiver domains dimerize with 2-fold rotational symmetry using their alpha4-beta5-alpha5 faces, while the effector domains bind to DNA direct repeats with tandem symmetry, implying a loss of intramolecular interactions.
Organizational Affiliation:
Center for Advanced Biotechnology and Medicine, Piscataway, NJ 08854, USA.
