6XZC

CryoEM structure of the ring-shaped virulence factor EspB from Mycobacterium tuberculosis

Summary for 6XZC

• Entry DOI: 10.2210/pdb6xzc/pdb
• Related: 3J83
• EMDB information: 10658
• Descriptor: ESX-1 secretion-associated protein EspB (1 entity in total)
• Functional Keywords: m. tuberculosis, esx-1, type vii secretion system, espb, rv3881c, esxa, cfp10, esat-6, transport protein
• Biological source: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
• Total number of polymer chains: 7
• Total formula weight: 333462.69

Authors

Piton, J.,Pojer, F.,Wakatsuki, S.,Gati, C.,Cole, S.T. (deposition date: 2020-02-03, release date: 2020-06-17, Last modification date: 2024-05-22)

Primary citation

Piton, J.,Pojer, F.,Wakatsuki, S.,Gati, C.,Cole, S.T.
High resolution CryoEM structure of the ring-shaped virulence factor EspB fromMycobacterium tuberculosis.
J Struct Biol X, 4:100029-100029, 2020

PubMed Abstract: The EspB protein of is a 60 kDa virulence factor, implicated in conjugation and exported by the ESX-1 system of which it may also be a component. Previous attempts to obtain high-resolution maps of EspB by cryo-electron microscopic examination of single particles have been thwarted by severe orientation bias of the particles. This was overcome by using detergent as a surfactant thereby allowing reconstruction of the EspB structure at 3.37 Å resolution. The final structure revealed the N-terminal domain of EspB to be organized as a cylindrical heptamer with dimensions of 90 Å x 90 Å and a central channel of 45 Å diameter whereas the C-terminal domain was unstructured. New atomic insight was obtained into the helical packing required for protomer interactions and the overall electrostatic potential. The external surface is electronegatively charged while the channel is lined with electropositive patches. EspB thus has many features of a pore-like transport protein that might allow the passage of an ESX-1 substrate such as the 35 Å diameter EsxA-EsxB heterodimer or B-form DNA consistent with its proposed role in DNA uptake.

PubMed: 32875288
DOI: 10.1016/j.yjsbx.2020.100029

Experimental method

ELECTRON MICROSCOPY (3.37 Å)