1ZN2

Low Resolution Structure of Response Regulator StyR

Summary for 1ZN2

• Entry DOI: 10.2210/pdb1zn2/pdb
• Related: 1YIO
• Descriptor: response regulatory protein, MAGNESIUM ION (2 entities in total)
• Functional Keywords: transcription regulation, styrene degradation, transcription regulator
• Biological source: Pseudomonas fluorescens
• Total number of polymer chains: 1
• Total formula weight: 23420.18

Authors

Milani, M.,Leoni, L.,Rampioni, G.,Zennaro, E.,Ascenzi, P.,Bolognesi, M. (deposition date: 2005-05-11, release date: 2005-09-27, Last modification date: 2024-02-14)

Primary citation

Milani, M.,Leoni, L.,Rampioni, G.,Zennaro, E.,Ascenzi, P.,Bolognesi, M.
An Active-like Structure in the Unphosphorylated StyR Response Regulator Suggests a Phosphorylation- Dependent Allosteric Activation Mechanism.
STRUCTURE, 13:1289-1297, 2005

PubMed Abstract: StyR belongs to the FixJ subfamily of signal transduction response regulators; it controls transcription of the styABCD operon coding for styrene catabolism in Pseudomonas fluorescens ST. The crystal structure of unphosphorylated StyR is reported at 2.2 A resolution. StyR is composed of an N-terminal regulatory domain (StyR-N) and a C-terminal DNA binding domain (StyR-C). The two domains are separated by an elongated linker alpha helix (34 residues), a new feature in known response regulator structures. StyR-C is structured similarly to the DNA binding domain of the response regulator NarL. StyR-N shows structural reorganization of the phosphate receiving region involved in activation/homodimerization: specific residues adopt an "active-like" conformation, and the alpha4 helix, involved in dimerization of the homologous FixJ response regulator, is trimmed to just one helical turn. Overall, structural considerations suggest that phosphorylation may act as an allosteric switch, shifting a preexisting StyR equilibrium toward the active, dimeric, DNA binding form.

PubMed: 16154086
DOI: 10.1016/j.str.2005.05.014

Experimental method

X-RAY DIFFRACTION (2.91 Å)