[English] 日本語
Yorodumi
- PDB-9n0x: Cryo-EM structure of human PSS2 -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 9n0x
TitleCryo-EM structure of human PSS2
ComponentsPhosphatidylserine synthase 2
KeywordsMEMBRANE PROTEIN / PS lipid
Function / homology
Function and homology information


CDP-diacylglycerol-serine O-phosphatidyltransferase activity / L-serine-phosphatidylethanolamine phosphatidyltransferase / L-serine-phosphatidylethanolamine phosphatidyltransferase activity / Synthesis of PS / phosphatidylserine biosynthetic process / transferase activity / endoplasmic reticulum membrane / membrane
Similarity search - Function
Phosphatidyl serine synthase / Phosphatidyl serine synthase
Similarity search - Domain/homology
Chem-P5S / Chem-RXY / Phosphatidylserine synthase 2
Similarity search - Component
Biological speciesHomo sapiens (human)
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.3 Å
AuthorsLi, D.Y. / Li, X.C.
Funding support United States, 1items
OrganizationGrant numberCountry
National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health & Human Development (NIH/NICHD) United States
CitationJournal: Proc Natl Acad Sci U S A / Year: 2025
Title: Molecular insights into human phosphatidylserine synthase 2 and its regulation of SREBP pathways.
Authors: Dongyu Li / Hongwen Chen / Goncalo Vale / Nadia Elghobashi-Meinhardt / Alexandra Hatton / Shunxing Rong / Jeffrey G McDonald / Xiaochun Li /
Abstract: Homologous proteins share similar sequences, enabling them to work together in cells to support normal physiological functions. Phosphatidylserine synthases 1 and 2 (PSS1 and PSS2) are homologous ...Homologous proteins share similar sequences, enabling them to work together in cells to support normal physiological functions. Phosphatidylserine synthases 1 and 2 (PSS1 and PSS2) are homologous enzymes that catalyze the synthesis of phosphatidylserine (PS) from different substrates. PSS2 shows a preference for phosphatidylethanolamine (PE) as its substrate, whereas PSS1 can utilize either PE or phosphatidylcholine. Previous studies showed that inhibiting PSS1 promotes SREBP-2 cleavage. Interestingly, despite their homology, our findings reveal that PSS2 exerts an opposing effect on the cleavage of both SREBP-1 and SREBP-2. We resolved the cryo-electron microscopy (cryo-EM) structure of human PSS2 at 3.3 Å resolution. Structural comparison of the catalytic cavities between PSS1 and PSS2 along with molecular dynamics simulations uncovers the molecular details behind the substrate preference of PSS2 for PE. The lipidomic analysis showed that PSS2 deficiency leads to PE accumulation in the endoplasmic reticulum, which has been shown to inhibit the cleavage of sterol regulatory element-binding proteins (SREBPs) in mice. Thus, our findings reveal the intricate network of intracellular phospholipid metabolism and underscore the distinct regulatory roles of homologous proteins in cellular activities.
History
DepositionJan 24, 2025Deposition site: RCSB / Processing site: RCSB
Revision 1.0May 7, 2025Provider: repository / Type: Initial release
Revision 1.0May 7, 2025Data content type: EM metadata / Data content type: EM metadata / Provider: repository / Type: Initial release
Revision 1.0May 7, 2025Data content type: FSC / Data content type: FSC / Provider: repository / Type: Initial release
Revision 1.0May 7, 2025Data content type: Half map / Part number: 1 / Data content type: Half map / Provider: repository / Type: Initial release
Revision 1.0May 7, 2025Data content type: Half map / Part number: 2 / Data content type: Half map / Provider: repository / Type: Initial release
Revision 1.0May 7, 2025Data content type: Image / Data content type: Image / Provider: repository / Type: Initial release
Revision 1.0May 7, 2025Data content type: Primary map / Data content type: Primary map / Provider: repository / Type: Initial release
Revision 1.1Jun 4, 2025Group: Data collection / Category: em_admin / em_software / Item: _em_admin.last_update / _em_software.name
Revision 1.1Jun 4, 2025Data content type: EM metadata / Data content type: EM metadata / EM metadata / Group: Data processing / Experimental summary / Data content type: EM metadata / EM metadata / Category: em_admin / em_software / Data content type: EM metadata / EM metadata / Item: _em_admin.last_update / _em_software.name
Revision 1.2Nov 19, 2025Group: Data collection / Database references / Category: citation / citation_author / em_admin
Item: _citation.country / _citation.journal_abbrev ..._citation.country / _citation.journal_abbrev / _citation.journal_id_ASTM / _citation.journal_id_CSD / _citation.journal_id_ISSN / _citation.journal_volume / _citation.page_first / _citation.page_last / _citation.pdbx_database_id_DOI / _citation.pdbx_database_id_PubMed / _citation.title / _citation.year / _em_admin.last_update

-
Structure visualization

Structure viewerMolecule:
MolmilJmol/JSmol

Downloads & links

-
Assembly

Deposited unit
A: Phosphatidylserine synthase 2
B: Phosphatidylserine synthase 2
hetero molecules


Theoretical massNumber of molelcules
Total (without water)117,29810
Polymers112,6172
Non-polymers4,6808
Water00
1


  • Idetical with deposited unit
  • defined by author&software
  • Evidence: electron microscopy, not applicable
TypeNameSymmetry operationNumber
identity operation1_555x,y,z1

-
Components

#1: Protein Phosphatidylserine synthase 2 / PSS-2 / PtdSer synthase 2 / Serine-exchange enzyme II


Mass: 56308.660 Da / Num. of mol.: 2
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Homo sapiens (human) / Gene: PTDSS2, PSS2 / Production host: Homo sapiens (human)
References: UniProt: Q9BVG9, L-serine-phosphatidylethanolamine phosphatidyltransferase
#2: Chemical
ChemComp-P5S / O-[(R)-{[(2R)-2,3-bis(octadecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-L-serine / phosphatidyl serine


Mass: 792.075 Da / Num. of mol.: 4 / Source method: obtained synthetically / Formula: C42H82NO10P / Feature type: SUBJECT OF INVESTIGATION
#3: Chemical ChemComp-CA / CALCIUM ION


Mass: 40.078 Da / Num. of mol.: 2 / Source method: obtained synthetically / Formula: Ca / Feature type: SUBJECT OF INVESTIGATION
#4: Chemical ChemComp-RXY / (7Z,19R,22R)-25-amino-22-hydroxy-16,22-dioxo-17,21,23-trioxa-22lambda~5~-phosphapentacos-7-en-19-yl (9Z)-octadec-9-enoate


Mass: 715.981 Da / Num. of mol.: 2 / Source method: obtained synthetically / Formula: C39H74NO8P / Feature type: SUBJECT OF INVESTIGATION
Has ligand of interestY
Has protein modificationY

-
Experimental details

-
Experiment

ExperimentMethod: ELECTRON MICROSCOPY
EM experimentAggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction

-
Sample preparation

ComponentName: Structure of human PSS2 / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT
Source (natural)Organism: Homo sapiens (human)
Source (recombinant)Organism: Homo sapiens (human)
Buffer solutionpH: 7.5
SpecimenConc.: 14 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES
VitrificationCryogen name: ETHANE

-
Electron microscopy imaging

Experimental equipment
Model: Titan Krios / Image courtesy: FEI Company
MicroscopyModel: TFS KRIOS
Electron gunElectron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM
Electron lensMode: BRIGHT FIELD / Nominal defocus max: 1800 nm / Nominal defocus min: 800 nm
Image recordingElectron dose: 60 e/Å2 / Film or detector model: FEI FALCON IV (4k x 4k)

-
Processing

EM softwareName: PHENIX / Category: model refinement
CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
3D reconstructionResolution: 3.3 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 93953 / Symmetry type: POINT
RefinementHighest resolution: 3.3 Å
Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS)
Refine LS restraints
Refine-IDTypeDev idealNumber
ELECTRON MICROSCOPYf_bond_d0.0026816
ELECTRON MICROSCOPYf_angle_d0.5139274
ELECTRON MICROSCOPYf_dihedral_angle_d14.908942
ELECTRON MICROSCOPYf_chiral_restr0.037986
ELECTRON MICROSCOPYf_plane_restr0.0051110

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242)：Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more