[English] 日本語
Yorodumi
- PDB-9rcv: Structure of the Human Peptide-Loading Complex Arrested by HCMV US6 -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 9rcv
TitleStructure of the Human Peptide-Loading Complex Arrested by HCMV US6
Components
  • (Antigen peptide transporter ...) x 2
  • Beta-2-microglobulin
  • MHC class I antigen
  • Tapasin
  • Unique short US6 glycoprotein
KeywordsIMMUNE SYSTEM / antigen processing / adaptive immunity / cryo-EM / ER chaperones / MHC class I / transporter associated with antigen processing
Function / homology
Function and homology information


MHC class Ib protein complex assembly / peptide antigen stabilization / Tapasin-ERp57 complex / MHC class I protein complex binding / antigen processing and presentation of endogenous peptide antigen via MHC class Ib via ER pathway, TAP-dependent / tapasin binding / ABC-type peptide antigen transporter activity / ABC-type antigen peptide transporter / TAP complex / ABC-type peptide transporter activity ...MHC class Ib protein complex assembly / peptide antigen stabilization / Tapasin-ERp57 complex / MHC class I protein complex binding / antigen processing and presentation of endogenous peptide antigen via MHC class Ib via ER pathway, TAP-dependent / tapasin binding / ABC-type peptide antigen transporter activity / ABC-type antigen peptide transporter / TAP complex / ABC-type peptide transporter activity / TAP2 binding / TAP1 binding / peptide antigen transport / MHC class Ib protein binding / cytosol to endoplasmic reticulum transport / symbiont-mediated suppression of host antigen processing and presentation of peptide antigen via MHC class I / regulation of protein complex stability / retrograde vesicle-mediated transport, Golgi to endoplasmic reticulum / peptide transport / peptide transmembrane transporter activity / TAP complex binding / antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-dependent / MHC class I protein binding / molecular sequestering activity / antigen processing and presentation of peptide antigen via MHC class I / endoplasmic reticulum-Golgi intermediate compartment membrane / protein folding chaperone / early endosome lumen / Nef mediated downregulation of MHC class I complex cell surface expression / DAP12 interactions / Endosomal/Vacuolar pathway / Antigen Presentation: Folding, assembly and peptide loading of class I MHC / negative regulation of iron ion transport / lumenal side of endoplasmic reticulum membrane / T cell mediated cytotoxicity / cellular response to iron(III) ion / negative regulation of forebrain neuron differentiation / antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent / ER to Golgi transport vesicle membrane / peptide antigen assembly with MHC class I protein complex / transferrin transport / regulation of erythrocyte differentiation / regulation of iron ion transport / negative regulation of receptor-mediated endocytosis / response to molecule of bacterial origin / MHC class I peptide loading complex / HFE-transferrin receptor complex / defense response / cellular response to iron ion / positive regulation of T cell cytokine production / antigen processing and presentation of endogenous peptide antigen via MHC class I / ADP binding / MHC class I protein complex / peptide antigen assembly with MHC class II protein complex / negative regulation of neurogenesis / positive regulation of receptor-mediated endocytosis / cellular response to nicotine / MHC class II protein complex / positive regulation of T cell mediated cytotoxicity / multicellular organismal-level iron ion homeostasis / transmembrane transport / specific granule lumen / centriolar satellite / peptide antigen binding / antigen processing and presentation of exogenous peptide antigen via MHC class II / phagocytic vesicle membrane / positive regulation of immune response / recycling endosome membrane / positive regulation of T cell activation / Interferon gamma signaling / negative regulation of epithelial cell proliferation / Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell / Modulation by Mtb of host immune system / positive regulation of cellular senescence / sensory perception of smell / unfolded protein binding / tertiary granule lumen / DAP12 signaling / MHC class II protein complex binding / T cell differentiation in thymus / late endosome membrane / protein transport / negative regulation of neuron projection development / ER-Phagosome pathway / regulation of gene expression / protein refolding / protein-containing complex assembly / early endosome membrane / amyloid fibril formation / protein homotetramerization / molecular adaptor activity / intracellular iron ion homeostasis / adaptive immune response / learning or memory / nuclear speck / immune response / host cell endoplasmic reticulum membrane / endoplasmic reticulum lumen / Amyloid fiber formation / Golgi membrane
Similarity search - Function
Viral unique short region 6 / Viral unique short region 6 / Tapasin / Antigen peptide transporter 2 / ABC transporter Tap-like / Type 1 protein exporter / : / ABC transporter transmembrane region / ABC transporter type 1, transmembrane domain / ABC transporter integral membrane type-1 fused domain profile. ...Viral unique short region 6 / Viral unique short region 6 / Tapasin / Antigen peptide transporter 2 / ABC transporter Tap-like / Type 1 protein exporter / : / ABC transporter transmembrane region / ABC transporter type 1, transmembrane domain / ABC transporter integral membrane type-1 fused domain profile. / MHC class I, alpha chain, C-terminal / MHC_I C-terminus / ABC transporter type 1, transmembrane domain superfamily / MHC class I alpha chain, alpha1 alpha2 domains / Class I Histocompatibility antigen, domains alpha 1 and 2 / Beta-2-Microglobulin / : / MHC class I-like antigen recognition-like / MHC class I-like antigen recognition-like superfamily / ABC transporter-like, conserved site / ABC transporters family signature. / MHC classes I/II-like antigen recognition protein / ABC transporter / ABC transporter-like, ATP-binding domain / ATP-binding cassette, ABC transporter-type domain profile. / : / Immunoglobulin/major histocompatibility complex, conserved site / Immunoglobulins and major histocompatibility complex proteins signature. / Immunoglobulin C-Type / Immunoglobulin C1-set / Immunoglobulin C1-set domain / Ig-like domain profile. / Immunoglobulin-like domain / Immunoglobulin-like domain superfamily / ATPases associated with a variety of cellular activities / AAA+ ATPase domain / Immunoglobulin-like fold / P-loop containing nucleoside triphosphate hydrolase
Similarity search - Domain/homology
ADENOSINE-5'-DIPHOSPHATE / ADENOSINE-5'-TRIPHOSPHATE / MHC class I antigen / Tapasin / Unique short US6 glycoprotein / Beta-2-microglobulin / Antigen peptide transporter 1 / Antigen peptide transporter 2
Similarity search - Component
Biological speciesHomo sapiens (human)
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.7 Å
AuthorsStolz, M. / Susac, L. / Trowitzsch, S. / Tampe, R.
Funding supportEuropean Union, Germany, United States, 5items
OrganizationGrant numberCountry
European Research Council (ERC)789121European Union
European Research Council (ERC)101141396European Union
German Research Foundation (DFG)TA157/12-1 Germany
German Research Foundation (DFG)CRC1507/P18 Germany
Other privateUR013222 United States
Citation
Journal: Sci Adv / Year: 2026
Title: Architectural principles of transporter-chaperone coupling within the native MHC I peptide-loading complex.
Authors: Milena Stolz / Lukas Sušac / Amin Fahim / Rieke Keller / Lisa Saggau / Filippo Mancia / Simon Trowitzsch / Robert Tampé /
Abstract: Adaptive immunity depends on major histocompatibility complex class I (MHC I) presentation of peptides, a process orchestrated by the peptide-loading complex (PLC) in the endoplasmic reticulum (ER). ...Adaptive immunity depends on major histocompatibility complex class I (MHC I) presentation of peptides, a process orchestrated by the peptide-loading complex (PLC) in the endoplasmic reticulum (ER). The PLC ensures precise peptide selection and loading and is a major target of viral immune evasion, notably by human cytomegalovirus (HCMV). Here, we report the 2.59- to 2.88-Å cryo-electron microscopy structure of native human PLC bound to the HCMV immune evasin US6. US6 inhibits the transporter associated with antigen processing 1/2 (TAP1/2) by laterally attaching its transmembrane helix to TAP2 using a disulfide-rich domain to mimic a translocating peptide. This domain blocks the ER-lumenal exit and locks TAP in an outward-facing conformation with closed nucleotide-binding domains and asymmetric adenosine 5'-triphosphate/adenosine 5'-diphosphate occlusion. The structure also reveals how TAP's amino-terminal transmembrane domains scaffold the MHC I chaperone tapasin. These findings elucidate the mechanism of US6-mediated immune evasion and highlight potential targets for therapeutic modulation of immune presentation in infection and cancer.
#1: Journal: Acta Crystallogr D Struct Biol / Year: 2019
Title: Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix.
Authors: Dorothee Liebschner / Pavel V Afonine / Matthew L Baker / Gábor Bunkóczi / Vincent B Chen / Tristan I Croll / Bradley Hintze / Li Wei Hung / Swati Jain / Airlie J McCoy / Nigel W Moriarty ...Authors: Dorothee Liebschner / Pavel V Afonine / Matthew L Baker / Gábor Bunkóczi / Vincent B Chen / Tristan I Croll / Bradley Hintze / Li Wei Hung / Swati Jain / Airlie J McCoy / Nigel W Moriarty / Robert D Oeffner / Billy K Poon / Michael G Prisant / Randy J Read / Jane S Richardson / David C Richardson / Massimo D Sammito / Oleg V Sobolev / Duncan H Stockwell / Thomas C Terwilliger / Alexandre G Urzhumtsev / Lizbeth L Videau / Christopher J Williams / Paul D Adams /
Abstract: Diffraction (X-ray, neutron and electron) and electron cryo-microscopy are powerful methods to determine three-dimensional macromolecular structures, which are required to understand biological ...Diffraction (X-ray, neutron and electron) and electron cryo-microscopy are powerful methods to determine three-dimensional macromolecular structures, which are required to understand biological processes and to develop new therapeutics against diseases. The overall structure-solution workflow is similar for these techniques, but nuances exist because the properties of the reduced experimental data are different. Software tools for structure determination should therefore be tailored for each method. Phenix is a comprehensive software package for macromolecular structure determination that handles data from any of these techniques. Tasks performed with Phenix include data-quality assessment, map improvement, model building, the validation/rebuilding/refinement cycle and deposition. Each tool caters to the type of experimental data. The design of Phenix emphasizes the automation of procedures, where possible, to minimize repetitive and time-consuming manual tasks, while default parameters are chosen to encourage best practice. A graphical user interface provides access to many command-line features of Phenix and streamlines the transition between programs, project tracking and re-running of previous tasks.
History
DepositionMay 29, 2025Deposition site: PDBE / Processing site: PDBE
Revision 1.0Dec 3, 2025Provider: repository / Type: Initial release
Revision 1.0Dec 3, 2025Data content type: EM metadata / Data content type: EM metadata / Provider: repository / Type: Initial release
Revision 1.0Dec 3, 2025Data content type: Image / Data content type: Image / Provider: repository / Type: Initial release
Revision 1.0Dec 3, 2025Data content type: Primary map / Data content type: Primary map / Provider: repository / Type: Initial release
Revision 1.1Feb 11, 2026Group: Data collection / Database references / Category: citation / citation_author / em_admin
Item: _citation.country / _citation.journal_abbrev ..._citation.country / _citation.journal_abbrev / _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
Revision 1.1Feb 11, 2026Data content type: EM metadata / Data content type: EM metadata / EM metadata / Group: Database references / Experimental summary / Data content type: EM metadata / EM metadata / EM metadata / Category: citation / citation_author / em_admin
Data content type: EM metadata / EM metadata ...EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata / EM metadata
Item: _citation.country / _citation.journal_abbrev ..._citation.country / _citation.journal_abbrev / _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: Antigen peptide transporter 1
B: Tapasin
C: MHC class I antigen
D: Beta-2-microglobulin
E: Antigen peptide transporter 2
F: Tapasin
G: MHC class I antigen
H: Beta-2-microglobulin
I: Unique short US6 glycoprotein
hetero molecules


Theoretical massNumber of molelcules
Total (without water)382,49717
Polymers380,2239
Non-polymers2,2748
Water724
1


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

-
Components

-
Antigen peptide transporter ... , 2 types, 2 molecules AE

#1: Protein Antigen peptide transporter 1 / APT1 / ATP-binding cassette sub-family B member 2 / Peptide supply factor 1 / Peptide transporter ...APT1 / ATP-binding cassette sub-family B member 2 / Peptide supply factor 1 / Peptide transporter PSF1 / PSF-1 / Peptide transporter TAP1 / Peptide transporter involved in antigen processing 1 / Really interesting new gene 4 protein / RING4


Mass: 81080.383 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / Cell line: Raji / Tissue: Burkitt lymphoma
References: UniProt: Q03518, ABC-type antigen peptide transporter
#5: Protein Antigen peptide transporter 2 / APT2 / ATP-binding cassette sub-family B member 3 / Peptide supply factor 2 / Peptide transporter ...APT2 / ATP-binding cassette sub-family B member 3 / Peptide supply factor 2 / Peptide transporter PSF2 / PSF-2 / Peptide transporter TAP2 / Peptide transporter involved in antigen processing 2 / Really interesting new gene 11 protein / RING11


Mass: 74697.242 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / Cell line: Raji / Tissue: Burkitt lymphoma
References: UniProt: Q03519, ABC-type antigen peptide transporter

-
Protein , 4 types, 7 molecules BFCGDHI

#2: Protein Tapasin / TPN / TPSN / NGS-17 / TAP-associated protein / TAP-binding protein


Mass: 47673.539 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / Cell line: Raji / Tissue: Burkitt lymphoma / References: UniProt: O15533
#3: Protein MHC class I antigen


Mass: 40480.973 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Details: HLA-B*15:10 / Source: (natural) Homo sapiens (human) / Cell line: Raji / Tissue: Burkitt lymphoma / References: UniProt: A0A678ZHF8
#4: Protein Beta-2-microglobulin


Mass: 13732.547 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / Cell line: Raji / Tissue: Burkitt lymphoma / References: UniProt: P61769
#6: Protein Unique short US6 glycoprotein / Protein HXLF6 / gpUS6


Mass: 20671.127 Da / Num. of mol.: 1
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Homo sapiens (human) / Gene: US6 / Production host: Homo sapiens (human) / References: UniProt: P14334

-
Sugars , 2 types, 4 molecules

#7: Polysaccharide 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose


Type: oligosaccharide / Mass: 424.401 Da / Num. of mol.: 2
Source method: isolated from a genetically manipulated source
DescriptorTypeProgram
DGlcpNAcb1-4DGlcpNAcb1-ROHGlycam Condensed SequenceGMML 1.0
WURCS=2.0/1,2,1/[a2122h-1b_1-5_2*NCC/3=O]/1-1/a4-b1WURCSPDB2Glycan 1.1.0
[][D-1-deoxy-GlcpNAc]{[(4+1)][b-D-GlcpNAc]{}}LINUCSPDB-CARE
#10: Sugar ChemComp-NAG / 2-acetamido-2-deoxy-beta-D-glucopyranose / N-acetyl-beta-D-glucosamine / 2-acetamido-2-deoxy-beta-D-glucose / 2-acetamido-2-deoxy-D-glucose / 2-acetamido-2-deoxy-glucose / N-ACETYL-D-GLUCOSAMINE


Type: D-saccharide, beta linking / Mass: 221.208 Da / Num. of mol.: 2 / Source method: obtained synthetically / Formula: C8H15NO6 / Feature type: SUBJECT OF INVESTIGATION
IdentifierTypeProgram
DGlcpNAcbCONDENSED IUPAC CARBOHYDRATE SYMBOLGMML 1.0
N-acetyl-b-D-glucopyranosamineCOMMON NAMEGMML 1.0
b-D-GlcpNAcIUPAC CARBOHYDRATE SYMBOLPDB-CARE 1.0
GlcNAcSNFG CARBOHYDRATE SYMBOLGMML 1.0

-
Non-polymers , 4 types, 8 molecules

#8: Chemical ChemComp-ATP / ADENOSINE-5'-TRIPHOSPHATE


Mass: 507.181 Da / Num. of mol.: 1 / Source method: obtained synthetically / Formula: C10H16N5O13P3 / Feature type: SUBJECT OF INVESTIGATION / Comment: ATP, energy-carrying molecule*YM
#9: Chemical ChemComp-MG / MAGNESIUM ION


Mass: 24.305 Da / Num. of mol.: 2 / Source method: obtained synthetically / Formula: Mg / Feature type: SUBJECT OF INVESTIGATION
#11: Chemical ChemComp-ADP / ADENOSINE-5'-DIPHOSPHATE


Mass: 427.201 Da / Num. of mol.: 1 / Source method: obtained synthetically / Formula: C10H15N5O10P2 / Feature type: SUBJECT OF INVESTIGATION / Comment: ADP, energy-carrying molecule*YM
#12: Water ChemComp-HOH / water


Mass: 18.015 Da / Num. of mol.: 4 / Source method: isolated from a natural source / Formula: H2O

-
Details

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: Human peptide-loading complex arrested by HCMV US6 / Type: COMPLEX / Entity ID: #1-#6 / Source: NATURAL
Molecular weight
IDEntity assembly-IDValue (°)Experimental value
110.570 MDaYES
21NO
Source (natural)Organism: Homo sapiens (human)
Buffer solutionpH: 6.5
Details: 20 mM HEPES-NaOH pH 6.5, 150 mM NaCl, 10 mM MgCl2, 2.5 mM biotin, 0.05% (w/v) glycodiosgenin
Buffer component
IDConc.NameFormulaBuffer-ID
120 mMHEPES-sodium hydroxideC8H18N2O4S-NaOH1
2150 mMsodium chlorideNaCl1
310 mMmagnesium chlorideMgCl21
40.05 %glycodiosgeninC56H92O251
52.5 mMbiotinC10H16N2O3S1
SpecimenConc.: 3.5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES
Specimen supportGrid material: GOLD / Grid mesh size: 300 divisions/in. / Grid type: UltrAuFoil
VitrificationInstrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K / Details: Blot force 5, Blot time 5 s

-
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 magnification: 105000 X / Calibrated magnification: 60241 X / Nominal defocus max: 1500 nm / Nominal defocus min: 500 nm / Cs: 2.7 mm
Specimen holderCryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER
Image recordingElectron dose: 58 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) / Num. of grids imaged: 3 / Num. of real images: 25454

-
Processing

EM softwareName: PHENIX / Category: model refinement
CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
Particle selectionNum. of particles selected: 726723
SymmetryPoint symmetry: C1 (asymmetric)
3D reconstructionResolution: 2.7 Å / Resolution method: OTHER / Num. of particles: 269213
Details: Composite map generated from 4 focus maps ranging 2.59 - 2.88 A
Symmetry type: POINT
RefinementCross valid method: NONE

+
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