3j83

Heptameric EspB Rosetta model guided by EM density

spinqualitylabelsall models 3j83, resolution 30.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3j83 is a 7 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Mycobacterium tuberculosis (Mtb) uses the ESX-1 type VII secretion system to export virulence proteins across its lipid-rich cell wall, which helps permeabilize the host's macrophage phagosomal membrane, facilitating the escape and cell-to-cell spread of Mtb. ESX-1 membranolytic activity depends on a set of specialized secreted Esp proteins, the structure and specific roles of which are not currently understood. Here, we report the X-ray and electron microscopic structures of the ESX-1-secreted EspB. We demonstrate that EspB adopts a PE/PPE-like fold that mediates oligomerization with apparent heptameric symmetry, generating a barrel-shaped structure with a central pore that we propose contributes to the macrophage killing functions of EspB. Our structural data also reveal unexpected direct interactions between the EspB bipartite secretion signal sequence elements that form a unified aromatic surface. These findings provide insight into how specialized proteins encoded within the ESX-1 locus are targeted for secretion, and for the first time indicate an oligomerization-dependent role for Esp virulence factors. Structure of EspB from the ESX-1 Type VII Secretion System and Insights into its Export Mechanism.,Solomonson M, Setiaputra D, Makepeace KA, Lameignere E, Petrotchenko EV, Conrady DG, Bergeron JR, Vuckovic M, DiMaio F, Borchers CH, Yip CK, Strynadka NC Structure. 2015 Mar 3;23(3):571-83. doi: 10.1016/j.str.2015.01.002. Epub 2015 Feb, 12. PMID:25684576 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA