4XWP: Structure Of Pe-ppe Domains Of Esx-1 Secreted Protein Espb, C2221 In Presence Of Ca

Mycobacterium tuberculosis secretes multiple virulence factors during infection via the general Sec and Tat pathways, and via specialized ESX secretion systems, also referred to as type VII secretion systems. The ESX-1 secretion system is an important virulence determinant because deletion of ESX-1 leads to attenuation of M. tuberculosis. ESX-1 secreted protein B (EspB) contains putative PE (Pro-Glu) and PPE (Pro-Pro-Glu) domains, and a C-terminal domain, which is processed by MycP1 protease during secretion. We determined the crystal structure of PE-PPE domains of EspB, which represents an all-helical, elongated molecule closely resembling the structure of the PE25-PPE41 heterodimer despite limited sequence similarity. Also, we determined the structure of full-length EspB, which does not have interpretable electron density for the C-terminal domain confirming that it is largely disordered. Comparative analysis of EspB in cell lysate and culture filtrates of M. tuberculosis revealed that mature secreted EspB forms oligomers. Electron microscopy analysis showed that the N-terminal fragment of EspB forms donut-shaped particles. These data provide a rationale for the future investigation of EspB's role in M. tuberculosis pathogenesis.
PDB ID: 4XWPDownload
MMDB ID: 127209
PDB Deposition Date: 2015/1/29
Updated in MMDB: 2017/09
Experimental Method:
x-ray diffraction
Resolution: 1.82  Å
Source Organism:
Similar Structures:
Biological Unit for 4XWP: monomeric; determined by author
Molecular Components in 4XWP
Label Count Molecule
Protein (1 molecule)
Esx-1 Secretion-associated Protein Espb(Gene symbol: espB)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB