Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 4-mer - A1B1C1D1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 335.08 kDa 
• Atom Count: 10,981 
• Modelled Residue Count: 1,392 
• Deposited Residue Count: 2,996 
• Unique protein chains: 3
• Unique nucleic acid chains: 1

 6W6W

Cryo-EM structure of CST bound to telomeric single-stranded DNA

• PDB DOI: 10.2210/pdb6W6W/pdb
• EM Map EMD-21567: EMDB EMDataResource

• Classification: STRUCTURAL PROTEIN/DNA
• Organism(s): Homo sapiens
• Expression System: Trichoplusia ni
• Mutation(s): No 


• Deposited: 2020-03-17 Released: 2020-06-03 
• Deposition Author(s): Lim, C., Barbour, A.T., Zaug, A.J., Goodrich, K.J., McKay, A.E., Wuttke, D.S., Cech, T.R.
• Funding Organization(s): Howard Hughes Medical Institute (HHMI), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), National Science Foundation (NSF, United States)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.00 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

The structure of human CST reveals a decameric assembly bound to telomeric DNA.

Lim, C.J., Barbour, A.T., Zaug, A.J., Goodrich, K.J., McKay, A.E., Wuttke, D.S., Cech, T.R.

(2020) Science 368: 1081-1085

• PubMed: 32499435 
• DOI: 10.1126/science.aaz9649
• Primary Citation of Related Structures:  
  6W6W


• PubMed Abstract: 
  

The CTC1-STN1-TEN1 (CST) complex is essential for telomere maintenance and resolution of stalled replication forks genome-wide. Here, we report the 3.0-angstrom cryo-electron microscopy structure of human CST bound to telomeric single-stranded DNA (ssDNA), which assembles as a decameric supercomplex. The atomic model of the 134-kilodalton CTC1 subunit, built almost entirely de novo, reveals the overall architecture of CST and the DNA-binding anchor site. The carboxyl-terminal domain of STN1 interacts with CTC1 at two separate docking sites, allowing allosteric mediation of CST decamer assembly. Furthermore, ssDNA appears to staple two monomers to nucleate decamer assembly. CTC1 has stronger structural similarity to Replication Protein A than the expected similarity to yeast Cdc13. The decameric structure suggests that CST can organize ssDNA analogously to the nucleosome's organization of double-stranded DNA.

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Organizational Affiliation: 

Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CST complex subunit CTC1	A, C [auth B]	1,233	Homo sapiens	Mutation(s): 0  Gene Names: CTC1, C17orf68
UniProt & NIH Common Fund Data Resources
Find proteins for Q2NKJ3 (Homo sapiens) Explore Q2NKJ3  Go to UniProtKB:  Q2NKJ3
PHAROS:  Q2NKJ3

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
CST complex subunit STN1	D [auth C]	374	Homo sapiens	Mutation(s): 0  Gene Names: STN1, OBFC1
UniProt & NIH Common Fund Data Resources
Find proteins for Q9H668 (Homo sapiens) Explore Q9H668  Go to UniProtKB:  Q9H668
PHAROS:  Q9H668

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
CST complex subunit TEN1	E [auth D]	152	Homo sapiens	Mutation(s): 0  Gene Names: TEN1, C17orf106
UniProt
Find proteins for Q86WV5 (Homo sapiens) Explore Q86WV5  Go to UniProtKB:  Q86WV5

Entity ID: 2
Molecule	Chains	Length	Organism	Image
DNA (5'-D(P*TP*AP*GP*G)-3')	B [auth E]	4	Homo sapiens

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN (Subject of Investigation/LOI)	F [auth A]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.00 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2020-06-03 
Deposition Author(s): Lim, C., Barbour, A.T., Zaug, A.J., Goodrich, K.J., McKay, A.E., Wuttke, D.S., Cech, T.R.

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Funding Organization	Location	Grant Number
Howard Hughes Medical Institute (HHMI)	United States	Tom Cech HHMI Investigator
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R01GM099705
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R01GM059414
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	K99GM131023
National Science Foundation (NSF, United States)	United States	MCB 1716425
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	T32GM008759

Revision History  

• Version 1.0: 2020-06-03
  Type: Initial release
  
• Version 1.1: 2020-06-17
  Changes: Database references