PXD060913

PXD060913 is an original dataset announced via ProteomeXchange.

Title	Two pairs of back-to-back α-helices of Kingella kingae RtxA toxin are crucial for the formation of a membrane pore
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 α-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 α-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.
HostingRepository	PRIDE
AnnounceDate	2025-02-18
AnnouncementXML	Submission_2025-02-18_02:13:55.720.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	David Jurnečka
SpeciesList	scientific name: Kingella sp. (in: b-proteobacteria); NCBI TaxID: 2020713;
ModificationList	myristoylated residue
Instrument	timsTOF SCP

Revision	Datetime	Status	ChangeLog Entry
0	2025-02-18 02:05:43	ID requested
⏵ 1	2025-02-18 02:13:56	announced

10.1016/J.IJBIOMAC.2024.137604;

submitter keyword: RTX toxins,Kingella kingae

Radim Osička
contact affiliation	Laboratory of Molecular Biology of Bacterial Pathogens Cell and Molecular Microbiology Division Institute of Microbiology, v.v.i. The Czech Academy of Sciences
contact email	osicka@biomed.cas.cz
lab head
David Jurnečka
contact affiliation	Institute of Microbiology, Czech Academy of Sciences
contact email	david.jurnecka@biomed.cas.cz
dataset submitter

Dataset FTP location NOTE: Most web browsers have now discontinued native support for FTP access within the browser window. But you can usually install another FTP app (we recommend FileZilla) and configure your browser to launch the external application when you click on this FTP link. Or otherwise, launch an app that supports FTP (like FileZilla) and use this address: ftp://ftp.pride.ebi.ac.uk/pride/data/archive/2025/02/PXD060913

PRIDE project URI

• PRIDE
  1. PXD060913
     1. Label: PRIDE project
     2. Name: Two pairs of back-to-back α-helices of Kingella kingae RtxA toxin are crucial for the formation of a membrane pore