1XJV | pdb_00001xjv

Crystal structure of human POT1 bound to telomeric single-stranded DNA (TTAGGGTTAG)

• PDB DOI: https://doi.org/10.2210/pdb1XJV/pdb
• NAKB: 1XJV

• Classification: TRANSCRIPTION/DNA
• Organism(s): Homo sapiens
• Expression System: Spodoptera frugiperda
• Mutation(s): No 


• Deposited: 2004-09-25 Released: 2004-12-14 
• Deposition Author(s): Lei, M., Podell, E.R., Cech, T.R.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.73 Å
• R-Value Free: 
  0.237 (Depositor), 0.254 (DCC) 
• R-Value Work: 
  0.228 (Depositor), 0.239 (DCC) 
• R-Value Observed: 
  0.232 (Depositor) 

Literature

Structure of human POT1 bound to telomeric single-stranded DNA provides a model for chromosome end-protection

Lei, M., Podell, E.R., Cech, T.R.

(2004) Nat Struct Mol Biol 11: 1223-1229

• PubMed: 15558049 
• DOI: https://doi.org/10.1038/nsmb867
• Primary Citation Related Structures: 
  1XJV


• PubMed Abstract: 
  

  The POT1 (protection of telomeres 1) protein binds the single-stranded overhang at the ends of chromosomes in diverse eukaryotes. It is essential for chromosome end-protection in the fission yeast Schizosaccharomyces pombe, and it is involved in regulation of telomere length in human cells. Here, we report the crystal structure at a resolution of 1.73 A of the N-terminal half of human POT1 (hPOT1) protein bound to a telomeric single-stranded DNA (ssDNA) decamer, TTAGGGTTAG, the minimum tight-binding sequence indicated by in vitro binding assays. The structure reveals that hPOT1 contains two oligonucleotide/ oligosaccharide-binding (OB) folds; the N-terminal OB fold binds the first six nucleotides, resembling the structure of the S. pombe Pot1pN-ssDNA complex, whereas the second OB fold binds and protects the 3' end of the ssDNA. These results provide an atomic-resolution model for chromosome end-capping.

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Organizational Affiliation: 
• Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 36.31 kDa 
• Atom Count: 2,766 
• Modeled Residue Count: 301 
• Deposited Residue Count: 304 
• Unique protein chains: 1
• Unique nucleic acid chains: 1

Macromolecules

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Protection of telomeres 1	B [auth A]	294	Homo sapiens	Mutation(s): 0  Gene Names: POT1
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NUX5 (Homo sapiens) Explore Q9NUX5  Go to UniProtKB:  Q9NUX5
PHAROS:  Q9NUX5 GTEx:  ENSG00000128513

Entity ID: 1
Molecule	Chains	Length	Organism	Image
hT10 d(TTAGGGTTAG)	A [auth B]	10	N/A

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.73 Å
• R-Value Free:  0.237 (Depositor), 0.254 (DCC) 
• R-Value Work:  0.228 (Depositor), 0.239 (DCC) 
• R-Value Observed: 0.232 (Depositor) 

Space Group: C 2 2 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 102.026	α = 90
b = 103.243	β = 90
c = 71.664	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
SCALEPACK	data scaling
CNS	refinement
HKL-2000	data reduction
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2004-12-14 
Deposition Author(s): Lei, M., Podell, E.R., Cech, T.R.

Revision History  

• Version 1.0: 2004-12-14
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-02-14
  Changes: Data collection, Database references