Structure of a central domain of human Ctc1

  • Classification: DNA BINDING PROTEIN
  • Organism(s): Homo sapiens
  • Expression System: Escherichia coli
  • Mutation(s): No 

  • Deposited: 2017-06-06 Released: 2017-11-29 
  • Deposition Author(s): Rice, C., Skordalakes, E.
  • Funding Organization(s): National Institutes of Health/National Cancer Institute (NIH/NCI), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

Experimental Data Snapshot

  • Resolution: 1.86 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.212 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


Structural and functional analysis of an OB-fold in human Ctc1 implicated in telomere maintenance and bone marrow syndromes.

Shastrula, P.K.Rice, C.T.Wang, Z.Lieberman, P.M.Skordalakes, E.

(2018) Nucleic Acids Res 46: 972-984

  • DOI: https://doi.org/10.1093/nar/gkx1213
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The human CST (Ctc1, Stn1 and Ten1) complex binds the telomeric overhang and regulates telomere length by promoting C-strand replication and inhibiting telomerase-dependent G-strand synthesis. Structural and biochemical studies on the human Stn1 and Ten1 complex revealed its mechanism of assembly and nucleic acid binding. However, little is known about the structural organization of the multi-domain Ctc1 protein and how each of these domains contribute to telomere length regulation. Here, we report the structure of a central domain of human Ctc1. The structure reveals a canonical OB-fold with the two identified disease mutations (R840W and V871M) contributing to the fold of the protein. In vitro assays suggest that although this domain is not contributing directly to Ctc1's substrate binding properties, it affects full-length Ctc1 localization to telomeres and Stn1-Ten1 binding. Moreover, functional assays show that deletion of the entire OB-fold domain leads to significant increase in telomere length, frequency of internal single G-strands and fragile telomeres. Our findings demonstrate that a previously unknown OB-fold domain contributes to efficient Ctc1 telomere localization and chromosome end maintenance.

  • Organizational Affiliation

    The Wistar Institute, Gene expression and regulation program, 3601 Spruce Street, Philadelphia, PA 19104, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CST complex subunit CTC1
A, B
168Homo sapiensMutation(s): 0 
Gene Names: CTC1C17orf68
UniProt & NIH Common Fund Data Resources
Find proteins for Q2NKJ3 (Homo sapiens)
Explore Q2NKJ3 
Go to UniProtKB:  Q2NKJ3
GTEx:  ENSG00000178971 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2NKJ3
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.86 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.212 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.537α = 90
b = 50.776β = 90
c = 144.538γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)United States1 RO1 CA201312-01
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States5 R01 GM088332-03

Revision History  (Full details and data files)

  • Version 1.0: 2017-11-29
    Type: Initial release
  • Version 1.1: 2018-01-03
    Changes: Database references
  • Version 1.2: 2018-02-07
    Changes: Database references
  • Version 1.3: 2019-12-04
    Changes: Author supporting evidence
  • Version 1.4: 2024-03-13
    Changes: Data collection, Database references, Derived calculations