Two pairs of back-to-back α-helices of Kingella kingae RtxA toxin are crucial for the formation of a membrane pore

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F24%3A10494306" target="_blank" >RIV/00216208:11310/24:10494306 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=LSZ73hxkIe" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=LSZ73hxkIe</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijbiomac.2024.137604" target="_blank" >10.1016/j.ijbiomac.2024.137604</a>

Result language

angličtina

Original language name

Two pairs of back-to-back α-helices of Kingella kingae RtxA toxin are crucial for the formation of a membrane pore

Original language description

The RtxA cytotoxin, a member of the RTX (Repeats in ToXin) family of pore-forming toxins, is the primary virulence factor of the paediatric facultative pathogen Kingella kingae. Although structure-function studies of RTX toxins have defined their characteristic domains and features, the exact membrane topology of RTX toxins remains unknown. Here, we used labelling of cell-bound RtxA with a membrane-impermeable, lysine-reactive reagent and subsequent detection of the labelled lysine residues by mass spectrometry, which revealed that most of the membrane-bound toxin is localised extracellularly. A trypsin protection assay with cell-bound RtxA demonstrated that five of seven transmembrane alpha-helices, predicted by various algorithms within the N-terminal half of the molecule, are irreversibly embedded in the membrane. Structure-function analysis showed that these alpha-helices, four of which are arranged as two pairs of back-to-back helices, are essential for the formation of an ion-conducting membrane pore. In contrast, the C-terminal half of RtxA is required for the interaction with the cell surface and for the irreversible insertion of the toxin into the membrane via acyl chains covalently linked to the molecule. These findings advance our understanding of the structure-function relationships of RtxA and enable us to propose a membrane topology model of the toxin.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10608 - Biochemistry and molecular biology

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

International Journal of Biological Macromolecules

ISSN

0141-8130

e-ISSN

1879-0003

Volume of the periodical

283

Issue of the periodical within the volume

Part 1

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

14

Pages from-to

137604

UT code for WoS article

001396174400001

EID of the result in the Scopus database

2-s2.0-85210019103