PXD060914

PXD060914 is an original dataset announced via ProteomeXchange.

Title	SND3 is the membrane insertase within a distinct SEC61 translocon complex
Description	During the biogenesis of most eukaryotic integral membrane proteins (IMPs), transmembrane domains are inserted into the endoplasmic reticulum membrane by a dedicated insertase or the SEC61 translocon. The SRP-independent (SND) pathway is the least understood route into the membrane, despite catering for a broad range of IMP types. Here, we show that Chaetomium thermophilum SND3 is a membrane insertase with an atypical fold. We further present a cryo-electron microscopy structure of a ribosome-associated SND3 translocon complex involved in co-translational IMP insertion. The structure reveals that the SND3 translocon additionally comprises the complete SEC61 translocon, CCDC47 and TRAPɑ. Here, the SEC61β N-terminus works together with CCDC47 to prevent substrate access to the translocon. Instead, molecular dynamics simulations show that SND3 disrupts the lipid bilayer to promote IMP insertion via its membrane-embedded hydrophilic groove. Structural and sequence comparisons indicate that the SND3 translocon is a distinct multipass translocon in fungi, euglenozoan parasites and other eukaryotic taxa.
HostingRepository	PRIDE
AnnounceDate	2025-09-24
AnnouncementXML	Submission_2025-09-24_09:21:07.297.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Julian Langer
SpeciesList	scientific name: Chaetomium thermophilum; NCBI TaxID: 209285;
ModificationList	monohydroxylated residue; acetylated residue; iodoacetamide derivatized residue
Instrument	Orbitrap Eclipse; timsTOF HT

Revision	Datetime	Status	ChangeLog Entry
0	2025-02-18 03:09:09	ID requested
⏵ 1	2025-09-24 09:21:07	announced

Dataset with its publication pending

submitter keyword: proteomics, multipass translocon, membrane insertase,SND3

Julian Langer
contact affiliation	Max Planck Institute of Biophysics
contact email	julian.langer@biophys.mpg.de
lab head
Julian Langer
contact affiliation	MPIs for Biophysics and Brain Research
contact email	julian.langer@biophys.mpg.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD060914
     1. Label: PRIDE project
     2. Name: SND3 is the membrane insertase within a distinct SEC61 translocon complex