PXD061837-1

PXD061837 is an original dataset announced via ProteomeXchange.

Title	Structural characterisation of the fungal Pmt4 homodimer - native MS and lipidomics
Description	Protein O-mannosyltransferases (PMTs) are conserved endoplasmic reticulum membrane embedded enzymes responsible for the transfer of mannose from dolichol phosphate-mannose (Dol-P-Man) to serine/threonine-rich protein substrates or unfolded proteins. PMTs from three subfamilies form obligate dimers with different substrate specificities, and require the concerted action of their transmembrane domains (TMDs) and a luminal MIR domain for catalysis. Here, we present structures, native mass spectrometry and structure-based mutagenesis of the Chaetomium thermophilum and Saccharomyces cerevisiae Pmt4 homodimers. The core fold of the TMDs and MIR domain is conserved with the Pmt1-Pmt2 heterodimer, indicating a shared catalytic mechanism. Distinct to Pmt4, the MIR domain interacts in cis with the TMDs of the same subunit and has a beta-hairpin insertion required for O-mannosylation of substrates. We further identify a cytosolic binding site for substrate Dol33 P-Man within the Pmt4 TMDs, which is conserved amongst PMTs and important for in vivo activity. Thus, we provide a framework to understand the substrate specificity and regulation of the Pmt4 homodimer.
HostingRepository	PRIDE
AnnounceDate	2025-11-19
AnnouncementXML	Submission_2025-11-19_07:59:12.825.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Francesco Fiorentino
SpeciesList	scientific name: Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719); NCBI TaxID: NEWT:759272; scientific name: Saccharomyces cerevisiae; NCBI TaxID: NCBITaxon:4932;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive UHMR; LTQ Orbitrap XL

Revision	Datetime	Status	ChangeLog Entry
0	2025-03-14 05:49:08	ID requested
⏵ 1	2025-11-19 07:59:13	announced

Dataset with its publication pending

submitter keyword: None

Carol V. Robinson
contact affiliation	Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
contact email	carol.robinson@chem.ox.ac.uk
lab head
Francesco Fiorentino
contact affiliation	Sapienza University of Rome
contact email	f.fiorentino@uniroma1.it
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/2025/11/PXD061837

PRIDE project URI

• PRIDE
  1. PXD061837
     1. Label: PRIDE project
     2. Name: Structural characterisation of the fungal Pmt4 homodimer - native MS and lipidomics