4GPK: Crystal Structure Of Nprr In Complex With Its Cognate Peptide Nprx

Citation:
Abstract
The transcriptional regulator NprR controls the expression of genes essential for the adaptative response of Bacillus cereus. NprR belongs to the RNPP family of directly regulated quorum sensors from Gram-positive bacteria. It is activated by the re-imported signaling peptide NprX. To elucidate the activation mechanism of this quorum-sensing system, we analyzed the conformation changes induced on binding of NprX. We solved the crystal structure of the NprR/NprX binary complex and characterized the apo form of NprR in solution. We demonstrated that apo NprR is a dimer that switches to a tetramer in the presence of NprX. Mutagenesis, and functional analysis allowed us to identify the protein and peptide residues directly involved in the NprR activation process. Based on the comparison with the Rap proteins, we propose a model for the peptide-induced conformational change allowing the apo dimer to switch to an active tetramer specifically recognizing target DNA sequences.
PDB ID: 4GPKDownload
MMDB ID: 111462
PDB Deposition Date: 2012/8/21
Updated in MMDB: 2013/09
Experimental Method:
x-ray diffraction
Resolution: 3.2  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 4GPK: octameric; determined by author
Molecular Components in 4GPK
Label Count Molecule
Proteins (8 molecules)
4
Nprr
Molecule annotation
4
Nprx Peptide
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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