5AEO

Virulence-associated protein VapG from the intracellular pathogen Rhodococcus equi

Summary for 5AEO

• Entry DOI: 10.2210/pdb5aeo/pdb
• Descriptor: R. EQUI VAPG PROTEIN, POTASSIUM ION (3 entities in total)
• Functional Keywords: immune system, beta barrel, bacterial pathogen, virulence protein, intracellular pathogen
• Biological source: RHODOCOCCUS EQUI
• Total number of polymer chains: 2
• Total formula weight: 34654.71

Authors

Okoko, T.,Blagova, E.V.,Whittingham, J.L.,Dover, L.G.,Wilkinson, A.J. (deposition date: 2015-01-07, release date: 2015-03-25, Last modification date: 2024-01-10)

Primary citation

Okoko, T.,Blagova, E.V.,Whittingham, J.L.,Dover, L.G.,Wilkinson, A.J.
Structural Characterisation of the Virulence-Associated Protein Vapg from the Horse Pathogen Rhodococcus Equi.
Vet.Microbiol., 179:42-, 2015

PubMed Abstract: Virulence and host range in Rhodococcus equi depends on the variable pathogenicity island of their virulence plasmids. Notable gene products are a family of small secreted virulence-associated proteins (Vaps) that are critical to intramacrophagic proliferation. Equine-adapted strains, which cause severe pyogranulomatous pneumonia in foals, produce a cell-associated VapA that is necessary for virulence, alongside five other secreted homologues. In the absence of biochemical insight, attention has turned to the structures of these proteins to develop a functional hypothesis. Recent studies have described crystal structures for VapD and a truncate of the VapA orthologue of porcine-adapted strains, VapB. Here, we crystallised the full-length VapG and determined its structure by molecular replacement. Electron density corresponding to the N-terminal domain was not visible suggesting that it is disordered. The protein core adopted a compact elliptical, anti-parallel β-barrel fold with β1-β2-β3-β8-β5-β6-β7-β4 topology decorated by a single peripheral α-helix unique to this family. The high glycine content of the protein allows close packing of secondary structural elements. Topologically, the surface has no indentations that indicate a nexus for molecular interactions. The distribution of polar and apolar groups on the surface of VapG is markedly uneven. One-third of the surface is dominated by exposed apolar side-chains, with no ionisable and only four polar side-chains exposed, giving rise to an expansive flat hydrophobic surface. Other surface regions are more polar, especially on or near the α-helix and a belt around the centre of the β-barrel. Possible functional significance of these recent structures is discussed.

PubMed: 25746683
DOI: 10.1016/J.VETMIC.2015.01.027

Experimental method

X-RAY DIFFRACTION (1.8 Å)