scholarly journals Cryo-EM structures of the translocational binary toxin complex CDTa-bound CDTb-pore from Clostridioides difficile

2021 ◽  
Author(s):  
Akihiro Kawamoto ◽  
Tomohito Yamada ◽  
Toru Yoshida ◽  
Takayuki Kato ◽  
Hideaki Tsuge
Keyword(s):  
High Resolution ◽  
Structural Information ◽  
Host Cells ◽  
Binary Toxin ◽  
Specific Interactions ◽  
Clostridioides Difficile ◽  
Toxin Complex ◽  
High Resolution Structure ◽  
Partial Unfolding ◽  
Resolution Structure

Abstract Besides two large cytotoxins (TcdA and TcdB), certain Clostridioides difficile strains also produce a binary toxin, called C. difficile toxin (CDT) composed of an enzymatic subunit involved in actin ADP-ribosylation (CDTa) and translocation pore (CDTb) that delivers CDTa into host cells through receptor-mediated endocytosis. CDTb is proposed to be a di-heptamer, but its physiological heptameric structure has not been reported to date. Here, we report the CDTa-bound CDTb-pore (heptamer) as a physiological complexes using cryo-EM. The high-resolution structure of the CDTa-bound CDTb-pore at 2.56-Å resolution revealed that CDTa binding to CDTb-pore induces partial unfolding and tilting of the first CDTa a-helix, and the translocation. In the CDTb-pore, the NSS-loop exists in “in” and “out” conformations, suggesting their involvement in substrate translocation through formation of weak, non-specific interactions. This structural information provides insights into drug design against hypervirulent C. difficile strains.

scholarly journals How electrostatic networks modulate specificity and stability of collagen

2018 ◽  
Vol 115 (24) ◽  
pp. 6207-6212 ◽  
Author(s):  
Hongning Zheng ◽  
Cheng Lu ◽  
Jun Lan ◽  
Shilong Fan ◽  
Vikas Nanda ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Hydrogen Bonding ◽  
High Resolution ◽  
Predictive Model ◽  
Self Assembly ◽  
Structural Information ◽  
Atomistic Simulations ◽  
Specific Interactions ◽  
Collagen Stability ◽  
Resolution Structure

One-quarter of the 28 types of natural collagen exist as heterotrimers. The oligomerization state of collagen affects the structure and mechanics of the extracellular matrix, providing essential cues to modulate biological and pathological processes. A lack of high-resolution structural information limits our mechanistic understanding of collagen heterospecific self-assembly. Here, the 1.77-Å resolution structure of a synthetic heterotrimer demonstrates the balance of intermolecular electrostatics and hydrogen bonding that affects collagen stability and heterospecificity of assembly. Atomistic simulations and mutagenesis based on the solved structure are used to explore the contributions of specific interactions to energetics. A predictive model of collagen stability and specificity is developed for engineering novel collagen structures.

High‐resolution structure of native toxin A from Clostridioides difficile

EMBO Reports ◽  
2021 ◽  
Author(s):  
Aria Aminzadeh ◽  
Christian Engelbrecht Larsen ◽  
Thomas Boesen ◽  
René Jørgensen
Keyword(s):  
High Resolution ◽  
Toxin A ◽  
Clostridioides Difficile ◽  
High Resolution Structure ◽  
Resolution Structure

scholarly journals The Importance of Therapeutically Targeting the Binary Toxin from Clostridioides difficile

2021 ◽  
Vol 22 (6) ◽  
pp. 2926
Author(s):  
Dinendra L. Abeyawardhane ◽  
Raquel Godoy-Ruiz ◽  
Kaylin A. Adipietro ◽  
Kristen M. Varney ◽  
Richard R. Rustandi ◽  
...  
Keyword(s):  
Host Cell ◽  
The Elderly ◽  
Cell Receptor ◽  
Host Cells ◽  
Binary Toxin ◽  
Clostridioides Difficile ◽  
Host Cell Receptor ◽  
Oligomeric Assembly ◽  
Nosocomial Disease ◽  
Binary Toxins

Novel therapeutics are needed to treat pathologies associated with the Clostridioides difficile binary toxin (CDT), particularly when C. difficile infection (CDI) occurs in the elderly or in hospitalized patients having illnesses, in addition to CDI, such as cancer. While therapies are available to block toxicities associated with the large clostridial toxins (TcdA and TcdB) in this nosocomial disease, nothing is available yet to treat toxicities arising from strains of CDI having the binary toxin. Like other binary toxins, the active CDTa catalytic subunit of CDT is delivered into host cells together with an oligomeric assembly of CDTb subunits via host cell receptor-mediated endocytosis. Once CDT arrives in the host cell’s cytoplasm, CDTa catalyzes the ADP-ribosylation of G-actin leading to degradation of the cytoskeleton and rapid cell death. Although a detailed molecular mechanism for CDT entry and host cell toxicity is not yet fully established, structural and functional resemblances to other binary toxins are described. Additionally, unique conformational assemblies of individual CDT components are highlighted herein to refine our mechanistic understanding of this deadly toxin as is needed to develop effective new therapeutic strategies for treating some of the most hypervirulent and lethal strains of CDT-containing strains of CDI.

scholarly journals High-resolution structure determination by continuous-rotation data collection in MicroED

2014 ◽  
Vol 11 (9) ◽  
pp. 927-930 ◽  
Author(s):  
Brent L Nannenga ◽  
Dan Shi ◽  
Andrew G W Leslie ◽  
Tamir Gonen
Keyword(s):  
High Resolution ◽  
Data Collection ◽  
Structure Determination ◽  
Continuous Rotation ◽  
High Resolution Structure ◽  
Resolution Structure

scholarly journals Tricks of the trade used to accelerate high-resolution structure determination of membrane proteins

FEBS Letters ◽  
2010 ◽  
Vol 584 (12) ◽  
pp. 2539-2547 ◽  
Author(s):  
Yo Sonoda ◽  
Alex Cameron ◽  
Simon Newstead ◽  
Hiroshi Omote ◽  
Yoshinori Moriyama ◽  
...  
Keyword(s):  
High Resolution ◽  
Membrane Proteins ◽  
Structure Determination ◽  
High Resolution Structure ◽  
Resolution Structure
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