PXD033157-1

PXD033157 is an original dataset announced via ProteomeXchange.

Title	Evidence for a widespread third system for bacterial polysaccharide export across the outer membrane comprising a composite OPX/β-barrel translocon
Description	Wzx/Wzy- and ABC transporter-dependent pathways, an outer membrane (OM) polysaccharide export (OPX) type translocon exports the polysaccharide across the OM. The paradigm OPX protein WzaE. coli is an octamer, in which the eight C-terminal domains form an α-helical OM pore, and the eight copies of the three N-terminal domains (D1-D3) a periplasmic cavity. In synthase-dependent pathways, the OM translocon is a 16- to 18-stranded β-barrel protein. In Myxococcus xanthus, the secreted polysaccharide EPS is synthesized in a Wzx/Wzy-dependent pathway. Here, using experiments and computational structural biology, we characterize EpsX as an OM 18-stranded β-barrel protein important for EPS synthesis and identify AlgE, a β-barrel translocon of a synthase-dependent pathway, as its closest structural homolog. We also find that EpsY, the OPX protein of the EPS pathway, only consists of the periplasmic D1 and D2 domains and lacks the domain for spanning the OM (henceforth D1D2OPX protein). In vivo, EpsX and EpsY mutually stabilize each other, supporting their direct interaction. Based on these observations, we propose a model whereby EpsY and EpsX make up a novel type of translocon for polysaccharide export across the OM. Specifically, in this composite translocon, EpsX functions as the OM-spanning translocon together with the periplasmic D1D2OPX protein EpsY. Based on computational genomics, similar composite systems are present widespread in Gram-negative bacteria. This model provides a framework for these proteins' future experimental characterization.
HostingRepository	PRIDE
AnnounceDate	2023-04-27
AnnouncementXML	Submission_2023-04-26_23:51:54.182.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	TimoGlatter
SpeciesList	scientific name: Myxococcus xanthus DK 1622; NCBI TaxID: 246197;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive HF

Revision	Datetime	Status	ChangeLog Entry
0	2022-04-11 08:22:48	ID requested
⏵ 1	2023-04-26 23:51:54	announced
2	2023-11-14 08:55:54	announced	2023-11-14: Updated project metadata.

submitter keyword: DIA,Myxococcus xanthus

TimoGlatter
contact affiliation	Max Planck Institute for Terrestrial Microbiology Karl-von-Frisch Str. 10 35043 Marburg Germany
contact email	glatter@mpi-marburg.mpg.de
lab head
TimoGlatter
contact affiliation	MPI Marburg
contact email	glatter@mpi-marburg.mpg.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD033157
     1. Label: PRIDE project
     2. Name: Evidence for a widespread third system for bacterial polysaccharide export across the outer membrane comprising a composite OPX/β-barrel translocon