PDBsum entry: 2axv

Transcription

PDB id: 2axv

Contents

Protein chains

302 a.a. *

Waters ×37

* Residue conservation analysis

PDB id:

2axv

Name:

Transcription

Title:

Structure of prgx y153c mutant

Structure:

Prgx. Chain: a, b, c, d. Engineered: yes. Mutation: yes

Source:

Enterococcus faecalis. Organism_taxid: 1351. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Tetramer (from PQS)

Resolution:

3.00Å R-factor: 0.242 R-free: 0.280

Authors:

K.Shi,C.K.Brown,Z.Y.Gu,B.K.Kozlowicz,G.M.Dunny, D.H.Ohlendorf,C.A.Earhart

Key ref:

K.Shi et al. (2005). Structure of peptide sex pheromone receptor PrgX and PrgX/pheromone complexes and regulation of conjugation in Enterococcus faecalis. Proc Natl Acad Sci U S A, 102, 18596-18601. PubMed id: 16339309 DOI: 10.1073/pnas.0506163102

Date:

06-Sep-05 Release date: 06-Dec-05

Protein chains

Q04114  (Q04114_ENTFA) -  Pheromone cCF10 receptor

Seq: 317 a.a.

Struc: 302 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 

• Biochemical function: DNA binding (3 terms)

DOI no: 10.1073/pnas.0506163102

Proc Natl Acad Sci U S A 102:18596-18601 (2005)

PubMed id: 16339309

Structure of peptide sex pheromone receptor PrgX and PrgX/pheromone complexes and regulation of conjugation in Enterococcus faecalis.

K.Shi, C.K.Brown, Z.Y.Gu, B.K.Kozlowicz, G.M.Dunny, D.H.Ohlendorf, C.A.Earhart.

ABSTRACT

Many bacterial activities, including expression of virulence factors, horizontal genetic transfer, and production of antibiotics, are controlled by intercellular signaling using small molecules. To date, understanding of the molecular mechanisms of peptide-mediated cell-cell signaling has been limited by a dearth of published information about the molecular structures of the signaling components. Here, we present the molecular structure of PrgX, a DNA- and peptide-binding protein that regulates expression of the conjugative transfer genes of the Enterococcus faecalis plasmid pCF10 in response to an intercellular peptide pheromone signal. Comparison of the structures of PrgX and the PrgX/pheromone complex suggests that pheromone binding destabilizes PrgX tetramers, opening a 70-bp pCF10 DNA loop required for conjugation repression.

Selected figure(s)

Figure 2.
Fig. 2. Topology of PrgX dimer. (a) Ribbon diagram of a PrgX homodimer showing the domain swapping of the N termini. Sites of PrgX mutations are shown with yellow and magenta balls. 12, 19, and 28 (in the N-terminal domains) are dominant negative mutants (B.K.K. and G.M.D., unpublished data) that lose the ability to bind DNA, most likely because they directly contact DNA. Mutations of residues 231, 235, and 261 (in the dimerization domains) affect PrgX dimerization (8, 10). Mutations of residues 284, 292, and 298 (in the C-terminal domain) cannot respond to cCF10 (8, 10). (b) Topology diagram for PrgX. N-terminal DNA-binding domain is shown in cyan. The dimerization/cCF10-binding domain is shown in green. The C-terminal regulatory domain is shown in red. The cCF10-binding domain is formed by two layers of -helices arranged as a left-handed superhelix.

Figure 4.
Fig. 4. Pheromone binding to PrgX. (a) Structural comparison of PrgX dimers formed by the WT uncomplexed protein (brown), WT PrgX/cCF10 complexes (green), and PrgX CT/cCF10 complexes (blue). The pheromone molecules are red. The C-terminal helix of uncomplexed PrgX is a cyan cylinder. The conformation of the C terminus in the cCF10 complex is pink. Upon the pheromone binding, the C-terminal helices swing 120° and refold into two -strands to cover the pheromone molecule in the binding pocket. (b) Connelly surface of the cCF10-binding pocket. A model of inhibitor peptide iCF10 is shown as colored sticks. (c) 2 F[c] - F[o] electron density map for the cCF10 molecule at the 1 level in the WT/cCF10 structure. The map was calculated before the cCF10 was built. (d) Interactions between the iCF10 and PrgX. The cCF10 molecule interacts with the C-terminal amino acid through the main chain. The amino acids at the bottom of the pocket interact with cCF10 through their side chains (CH···O hydrogen bond not shown).

Figures were selected by an automated process.