8XCH | pdb_00008xch

SARS-CoV-2 Replication-Transcription Complex has a dimer-of-dimeric architecture (ddRTC) in pre-capping initiation.


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.40 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural basis for the concurrence of template recycling and RNA capping in SARS-CoV-2.

Yan, L.Huang, Y.Liu, Y.Ge, J.Gao, S.Tan, L.Liu, L.Liu, Z.Ye, S.Wang, J.Xiong, J.Zhou, Y.Zhao, H.Zhao, X.Guddat, L.W.Gao, Y.Zhu, L.Rao, Z.Lou, Z.

(2025) Cell 

  • DOI: https://doi.org/10.1016/j.cell.2025.09.022
  • Primary Citation of Related Structures:  
    8XCH, 9IMK, 9IMM

  • PubMed Abstract: 

    In the SARS-CoV-2 replication-transcription complex (RTC), the nascent template-product duplex is unwound into a template strand for recycling and a product strand that needs to be capped. Here, we determined structures of the SARS-CoV-2 RTC in the pre- and post-capping initiation (CI) states. In the pre-CI state, the RTC has a dimer-of-dimeric architecture (ddRTC). The upstream RNA duplex in one RTC is reciprocally unwound by a helicase in a head-to-head-positioned RTC in the 3'-5' direction. The helicases bind either ADP or ADP⋅P i in their ATP-binding pockets, suggesting a mechanism for ATP-hydrolysis-driven unwinding. In the post-CI state, the binding of nsp9 to the nsp12 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) disrupts the ddRTC. The N terminus of nsp9 and the triphosphorylated 5' end of the product strand co-localize in NiRAN's catalytic site, exhibiting the state prior to nsp9 RNAylation for capping. These results provide an insight into the concurrence of template recycling and RNA capping in the SARS-CoV-2 RTC.


  • Organizational Affiliation
    • MOE Key Laboratory of Protein Science, School of Basic Medical Sciences, Tsinghua University, Beijing 100084, China; Guangzhou National Laboratory, Guangzhou 510005, China; State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.

Macromolecules

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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Replicase polyprotein 1ab
A, I, Q, Y
942Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
Gene Names: rep1a-1b
EC: 3.4.19.12 (PDB Primary Data), 3.4.22 (PDB Primary Data), 3.4.22.69 (PDB Primary Data), 2.7.7.48 (PDB Primary Data), 3.6.4.12 (PDB Primary Data), 3.6.4.13 (PDB Primary Data), 3.1.13 (PDB Primary Data), 3.1 (PDB Primary Data), 2.1.1 (PDB Primary Data)
UniProt
Find proteins for P0DTD1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTD1 
Go to UniProtKB:  P0DTD1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTD1
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Non-structural protein 8
B,
BA [auth b],
D,
J,
L,
R,
T,
Z
198Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
Gene Names: rep1a-1b
UniProt
Find proteins for P0DTD1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTD1 
Go to UniProtKB:  P0DTD1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTD1
Sequence Annotations
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Non-structural protein 7AA [auth a],
C,
K,
S
83Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
UniProt
Find proteins for P0DTC1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTC1 
Go to UniProtKB:  P0DTC1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTC1
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  • Reference Sequence
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Entity ID: 4
MoleculeChains Sequence LengthOrganismDetailsImage
Helicase601Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
UniProt
Find proteins for P0DTD1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTD1 
Go to UniProtKB:  P0DTD1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTD1
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  • Reference Sequence
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Entity ID: 5
MoleculeChains LengthOrganismImage
RNA (39-MER)EA [auth e],
G,
O,
W
39synthetic construct
Sequence Annotations
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  • Reference Sequence
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Entity ID: 6
MoleculeChains LengthOrganismImage
RNA (39-MER)FA [auth f],
H,
P,
X
39synthetic construct
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ADP (Subject of Investigation/LOI)
Query on ADP

Download Ideal Coordinates CCD File 
LA [auth E],
PB [auth d]
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
PO4 (Subject of Investigation/LOI)
Query on PO4

Download Ideal Coordinates CCD File 
QB [auth d]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
ZN (Subject of Investigation/LOI)
Query on ZN

Download Ideal Coordinates CCD File 
AB [auth U]
BB [auth U]
CB [auth U]
DB [auth V]
EB [auth V]
AB [auth U],
BB [auth U],
CB [auth U],
DB [auth V],
EB [auth V],
FB [auth V],
GA [auth A],
GB [auth Y],
HA [auth A],
HB [auth Y],
IA [auth E],
JA [auth E],
JB [auth c],
KA [auth E],
KB [auth c],
LB [auth c],
MA [auth F],
MB [auth d],
NA [auth F],
NB [auth d],
OA [auth F],
OB [auth d],
PA [auth I],
QA [auth I],
SA [auth M],
TA [auth M],
UA [auth M],
VA [auth N],
WA [auth N],
XA [auth N],
YA [auth Q],
ZA [auth Q]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
MG (Subject of Investigation/LOI)
Query on MG

Download Ideal Coordinates CCD File 
IB [auth Y],
RA [auth I]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.40 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Science and Technology (MoST, China)China2024YFC2607300
National Natural Science Foundation of China (NSFC)China32371258
National Natural Science Foundation of China (NSFC)China82341073

Revision History  (Full details and data files)

  • Version 1.0: 2025-06-11
    Type: Initial release
  • Version 1.1: 2025-11-12
    Changes: Data collection, Database references