Cargando…

Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State

Diffocins are high-molecular-weight phage tail-like bacteriocins (PTLBs) that some Clostridium difficile strains produce in response to SOS induction. Similar to the related R-type pyocins from Pseudomonas aeruginosa, R-type diffocins act as molecular puncture devices that specifically penetrate the...

Descripción completa

Detalles Bibliográficos
Autores principales: Schwemmlein, Nina, Pippel, Jan, Gazdag, Emerich-Mihai, Blankenfeldt, Wulf
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6088184/
https://www.ncbi.nlm.nih.gov/pubmed/30127773
http://dx.doi.org/10.3389/fmicb.2018.01750
_version_ 1783346799163998208
author Schwemmlein, Nina
Pippel, Jan
Gazdag, Emerich-Mihai
Blankenfeldt, Wulf
author_facet Schwemmlein, Nina
Pippel, Jan
Gazdag, Emerich-Mihai
Blankenfeldt, Wulf
author_sort Schwemmlein, Nina
collection PubMed
description Diffocins are high-molecular-weight phage tail-like bacteriocins (PTLBs) that some Clostridium difficile strains produce in response to SOS induction. Similar to the related R-type pyocins from Pseudomonas aeruginosa, R-type diffocins act as molecular puncture devices that specifically penetrate the cell envelope of other C. difficile strains to dissipate the membrane potential and kill the attacked bacterium. Thus, R-type diffocins constitute potential therapeutic agents to counter C. difficile-associated infections. PTLBs consist of rigid and contractile protein complexes. They are composed of a baseplate, receptor-binding tail fibers and an inner needle-like tube surrounded by a contractile sheath. In the mature particle, the sheath and tube structure form a complex network comprising up to 200 copies of a sheath and a tube protein each. Here, we report the crystal structures together with small angle X-ray scattering data of the sheath and tube proteins CD1363 (39 kDa) and CD1364 (16 kDa) from C. difficile strain CD630 in a monomeric pre-assembly form at 1.9 and 1.5 Å resolution, respectively. The tube protein CD1364 displays a compact fold and shares highest structural similarity with a tube protein from Bacillus subtilis but is remarkably different from that of the R-type pyocin from P. aeruginosa. The structure of the R-type diffocin sheath protein, on the other hand, is highly conserved. It contains two domains, whereas related members such as bacteriophage tail sheath proteins comprise up to four, indicating that R-type PTLBs may represent the minimal protein required for formation of a complete sheath structure. Comparison of CD1363 and CD1364 with structures of PTLBs and related assemblies suggests that several conformational changes are required to form complete assemblies. In the sheath, rearrangement of the flexible N- and C-terminus enables extensive interactions between the other subunits, whereas for the tube, such contacts are primarily established by mobile α-helices. Together, our results combined with information from structures of homologous assemblies allow constructing a preliminary model of the sheath and tube assembly from R-type diffocin.
format Online
Article
Text
id pubmed-6088184
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-60881842018-08-20 Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State Schwemmlein, Nina Pippel, Jan Gazdag, Emerich-Mihai Blankenfeldt, Wulf Front Microbiol Microbiology Diffocins are high-molecular-weight phage tail-like bacteriocins (PTLBs) that some Clostridium difficile strains produce in response to SOS induction. Similar to the related R-type pyocins from Pseudomonas aeruginosa, R-type diffocins act as molecular puncture devices that specifically penetrate the cell envelope of other C. difficile strains to dissipate the membrane potential and kill the attacked bacterium. Thus, R-type diffocins constitute potential therapeutic agents to counter C. difficile-associated infections. PTLBs consist of rigid and contractile protein complexes. They are composed of a baseplate, receptor-binding tail fibers and an inner needle-like tube surrounded by a contractile sheath. In the mature particle, the sheath and tube structure form a complex network comprising up to 200 copies of a sheath and a tube protein each. Here, we report the crystal structures together with small angle X-ray scattering data of the sheath and tube proteins CD1363 (39 kDa) and CD1364 (16 kDa) from C. difficile strain CD630 in a monomeric pre-assembly form at 1.9 and 1.5 Å resolution, respectively. The tube protein CD1364 displays a compact fold and shares highest structural similarity with a tube protein from Bacillus subtilis but is remarkably different from that of the R-type pyocin from P. aeruginosa. The structure of the R-type diffocin sheath protein, on the other hand, is highly conserved. It contains two domains, whereas related members such as bacteriophage tail sheath proteins comprise up to four, indicating that R-type PTLBs may represent the minimal protein required for formation of a complete sheath structure. Comparison of CD1363 and CD1364 with structures of PTLBs and related assemblies suggests that several conformational changes are required to form complete assemblies. In the sheath, rearrangement of the flexible N- and C-terminus enables extensive interactions between the other subunits, whereas for the tube, such contacts are primarily established by mobile α-helices. Together, our results combined with information from structures of homologous assemblies allow constructing a preliminary model of the sheath and tube assembly from R-type diffocin. Frontiers Media S.A. 2018-08-03 /pmc/articles/PMC6088184/ /pubmed/30127773 http://dx.doi.org/10.3389/fmicb.2018.01750 Text en Copyright © 2018 Schwemmlein, Pippel, Gazdag and Blankenfeldt. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Schwemmlein, Nina
Pippel, Jan
Gazdag, Emerich-Mihai
Blankenfeldt, Wulf
Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State
title Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State
title_full Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State
title_fullStr Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State
title_full_unstemmed Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State
title_short Crystal Structures of R-Type Bacteriocin Sheath and Tube Proteins CD1363 and CD1364 From Clostridium difficile in the Pre-assembled State
title_sort crystal structures of r-type bacteriocin sheath and tube proteins cd1363 and cd1364 from clostridium difficile in the pre-assembled state
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6088184/
https://www.ncbi.nlm.nih.gov/pubmed/30127773
http://dx.doi.org/10.3389/fmicb.2018.01750
work_keys_str_mv AT schwemmleinnina crystalstructuresofrtypebacteriocinsheathandtubeproteinscd1363andcd1364fromclostridiumdifficileinthepreassembledstate
AT pippeljan crystalstructuresofrtypebacteriocinsheathandtubeproteinscd1363andcd1364fromclostridiumdifficileinthepreassembledstate
AT gazdagemerichmihai crystalstructuresofrtypebacteriocinsheathandtubeproteinscd1363andcd1364fromclostridiumdifficileinthepreassembledstate
AT blankenfeldtwulf crystalstructuresofrtypebacteriocinsheathandtubeproteinscd1363andcd1364fromclostridiumdifficileinthepreassembledstate