1XHE

Crystal structure of the receiver domain of redox response regulator arca

Summary for 1XHE

• Entry DOI: 10.2210/pdb1xhe/pdb
• Related: 1XHF
• Descriptor: Aerobic respiration control protein arcA (2 entities in total)
• Functional Keywords: two-component system; gene regulation; transcription factor; anoxic redox control; doubly wound five-stranded beta/alpha fold, transcription
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 28005.95

Authors

Toro-Roman, A.,Mack, T.R.,Stock, A.M. (deposition date: 2004-09-18, release date: 2005-05-17, Last modification date: 2024-04-03)

Primary citation

Toro-Roman, A.,Mack, T.R.,Stock, A.M.
Structural Analysis and Solution Studies of the Activated Regulatory Domain of the Response Regulator ArcA: A Symmetric Dimer Mediated by the alpha4-beta5-alpha5 Face
J.Mol.Biol., 349:11-26, 2005

PubMed Abstract: Escherichia coli react to changes from aerobic to anaerobic conditions of growth using the ArcA-ArcB two-component signal transduction system. This system, in conjunction with other proteins, regulates the respiratory metabolic pathways in the organism. ArcA is a member of the OmpR/PhoB subfamily of response regulator transcription factors that are known to regulate transcription by binding in tandem to target DNA direct repeats. It is still unclear in this subfamily how activation by phosphorylation of the regulatory domain of response regulators stimulates DNA binding by the effector domain and how dimerization and domain orientation, as well as intra- and intermolecular interactions, affect this process. In order to address these questions we have solved the crystal structures of the regulatory domain of ArcA in the presence and absence of the phosphoryl analog, BeF3-. In the crystal structures, the regulatory domain of ArcA forms a symmetric dimer mediated by the alpha4-beta5-alpha5 face of the protein and involving a number of residues that are highly conserved in the OmpR/PhoB subfamily. It is hypothesized that members of this subfamily use a common mechanism of regulation by dimerization. Additional biophysical studies were employed to probe the oligomerization state of ArcA, as well as its individual domains, in solution. The solution studies show the propensity of the individual domains to associate into oligomers larger than the dimer observed for the intact protein, and suggest that the C-terminal DNA-binding domain also plays a role in oligomerization.

PubMed: 15876365
DOI: 10.1016/j.jmb.2005.03.059

Experimental method

X-RAY DIFFRACTION (2.5 Å)