High-resolution cryo-EM structures of the E. Coli hemolysin ClyA oligomers

Wei Peng, Marcela de Souza Santos, Yang Li, Diana R. Tomchick, Kim Orth

Research output: Contribution to journalArticle

Abstract

Pore-forming proteins (PFPs) represent a functionally important protein family, that are found in organisms from viruses to humans. As a major branch of PFPs, bacteria pore-forming toxins (PFTs) permeabilize membranes and usually cause the death of target cells. E. coli hemolysin ClyA is the first member with the pore complex structure solved among α-PFTs, employing α-helices as transmembrane elements. ClyA is proposed to form pores composed of various numbers of protomers. With high-resolution cryo-EM structures, we observe that ClyA pore complexes can exist as newly confirmed oligomers of a tridecamer and a tetradecamer, at estimated resolutions of 3.2 Å and 4.3 Å, respectively. The 2.8 Å cryo-EM structure of a dodecamer dramatically improves the existing structural model. Structural analysis indicates that protomers from distinct oligomers resemble each other and neighboring protomers adopt a conserved interaction mode. We also show a stabilized intermediate state of ClyA during the transition process from soluble monomers to pore complexes. Unexpectedly, even without the formation of mature pore complexes, ClyA can permeabilize membranes and allow leakage of particles less than ~400 Daltons. In addition, we are the first to show that ClyA forms pore complexes in the presence of cholesterol within artificial liposomes. These findings provide new mechanistic insights into the dynamic process of pore assembly for the prototypical α-PFT ClyA.

Original languageEnglish (US)
Article numbere0213423
JournalPloS one
Volume14
Issue number5
DOIs
StatePublished - May 1 2019

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hemolysins
Protein Subunits
protein subunits
Oligomers
Porins
toxins
Escherichia coli
liposomes (artificial)
Membranes
Proteins
proteins
Structural Models
Viruses
Structural analysis
Liposomes
Cause of Death
Bacteria
Monomers
Cholesterol
cholesterol

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

High-resolution cryo-EM structures of the E. Coli hemolysin ClyA oligomers. / Peng, Wei; de Souza Santos, Marcela; Li, Yang; Tomchick, Diana R.; Orth, Kim.

In: PloS one, Vol. 14, No. 5, e0213423, 01.05.2019.

Research output: Contribution to journalArticle

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