PDBsum entry 2vs0

Cell invasion

PDB id: 2vs0

Contents

Protein chains

83 a.a. *

Ligands

CAC

Metals

_ZN ×5

Waters ×174

* Residue conservation analysis

PDB id:

2vs0

Name:

Cell invasion

Title:

Structural analysis of homodimeric staphylococcal aureus virulence factor esxa

Structure:

Virulence factor esxa. Chain: a, b. Engineered: yes

Source:

Staphylococcus aureus. Organism_taxid: 1280. Strain: mu50. Atcc: 700699. Expressed in: escherichia coli. Expression_system_taxid: 511693. Other_details: genomic DNA

Resolution:

1.40Å R-factor: 0.169 R-free: 0.218

Authors:

R.Sundaramoorthy,P.K.Fyfe,W.N.Hunter

Key ref:

R.Sundaramoorthy et al. (2008). Structure of Staphylococcus aureus EsxA suggests a contribution to virulence by action as a transport chaperone and/or adaptor protein. J Mol Biol, 383, 603-614. PubMed id: 18773907 DOI: 10.1016/j.jmb.2008.08.047

Date:

17-Apr-08 Release date: 26-Aug-08

Protein chains

Q99WU4  (ESXA_STAAM) -  Type VII secretion system extracellular protein A from Staphylococcus aureus (strain Mu50 / ATCC 700699)

Seq: 97 a.a.

Struc: 83 a.a.

DOI no: 10.1016/j.jmb.2008.08.047

J Mol Biol 383:603-614 (2008)

PubMed id: 18773907

Structure of Staphylococcus aureus EsxA suggests a contribution to virulence by action as a transport chaperone and/or adaptor protein.

R.Sundaramoorthy, P.K.Fyfe, W.N.Hunter.

ABSTRACT

Staphylococcus aureus pathogenesis depends on a specialized protein secretion system (ESX-1) that delivers a range of virulence factors to assist infectivity. We report the characterization of two such factors, EsxA and EsxB, small acidic dimeric proteins carrying a distinctive WXG motif. EsxA crystallized in triclinic and monoclinic forms and high-resolution structures were determined. The asymmetric unit of each crystal form is a dimer. The EsxA subunit forms an elongated cylindrical structure created from side-by-side alpha-helices linked with a hairpin bend formed by the WXG motif. Approximately 25% of the solvent accessible surface area of each subunit is involved in interactions, predominantly hydrophobic, with the partner subunit. Secondary-structure predictions suggest that EsxB displays a similar structure. The WXG motif helps to create a shallow cleft at each end of the dimer, forming a short beta-sheet-like feature with an N-terminal segment of the partner subunit. Structural and sequence comparisons, exploiting biological data on related proteins found in Mycobacterium tuberculosis, suggest that this family of proteins may contribute to pathogenesis by transporting protein cargo through the ESX-1 system exploiting a C-terminal secretion signal and/or are capable of acting as adaptor proteins to facilitate interactions with host receptor proteins.

Selected figure(s)

Figure 2.
Fig. 2. The SaEsxA dimer. A ribbon diagram with subunit colored red (subunit A) and blue (subunit B) with helices labeled. The orientation of subunit A is similar to that shown in Fig. 1. Trp43 and Pro60 residues are shown as black van der Waals spheres.

Figure 5.
Fig. 5. Comparison with ESAT-6. Stereo diagram showing the structural overlay of SaEsxA on ESAT-6. SaEsxA is depicted in red and ESAT-6 in gray. Residues of ESAT-6 mutated to investigate function and the corresponding structurally aligned residues of SaEsxA are shown in sticks and labeled. The partner subunit of the SaEsxA dimer is shown in van der Waals surface representation and colored cyan.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2008, 383, 603-614) copyright 2008.

Figures were selected by the author.