1QZH

Crystal structure of Pot1 (protection of telomere)- ssDNA complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.283 
  • R-Value Work: 0.249 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

DNA self-recognition in the structure of Pot1 bound to telomeric single-stranded DNA

Lei, M.Podell, E.R.Baumann, P.Cech, T.R.

(2003) Nature 426: 198-203

  • DOI: 10.1038/nature02092
  • Primary Citation of Related Structures:  1QZG

  • PubMed Abstract: 
  • Telomeres, specialized protein-DNA complexes that cap the ends of linear chromosomes, are essential for protecting chromosomes from degradation and end-to-end fusions. The Pot1 (protection of telomeres 1) protein is a widely distributed eukaryotic en ...

    Telomeres, specialized protein-DNA complexes that cap the ends of linear chromosomes, are essential for protecting chromosomes from degradation and end-to-end fusions. The Pot1 (protection of telomeres 1) protein is a widely distributed eukaryotic end-capping protein, having been identified in fission yeast, microsporidia, plants and animals. Schizosaccharomyces pombe Pot1p is essential for telomere maintenance, and human POT1 has been implicated in telomerase regulation. Pot1 binds telomeric single-stranded DNA (ssDNA) with exceptionally high sequence specificity, the molecular basis of which has been unknown. Here we describe the 1.9-A-resolution crystal structure of the amino-terminal DNA-binding domain of S. pombe Pot1p complexed with ssDNA. The protein adopts an oligonucleotide/oligosaccharide-binding (OB) fold with two loops that protrude to form a clamp for ssDNA binding. The structure explains the sequence specificity of binding: in the context of the Pot1 protein, DNA self-recognition involving base-stacking and unusual G-T base pairs compacts the DNA. Any sequence change disrupts the ability of the DNA to form this structure, preventing it from contacting the array of protein hydrogen-bonding groups. The structure also explains how Pot1p avoids binding the vast excess of RNA in the nucleus.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Protection of telomeres protein 1
A, B, C, D, E, F
187Schizosaccharomyces pombe (strain 972 / ATCC 24843)Gene Names: pot1
Find proteins for O13988 (Schizosaccharomyces pombe (strain 972 / ATCC 24843))
Go to UniProtKB:  O13988
Entity ID: 1
MoleculeChainsLengthOrganism
telomeric single-stranded DNAG,H,I,J,K,L6N/A
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.283 
  • R-Value Work: 0.249 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 131.614α = 90.00
b = 76.329β = 115.21
c = 140.130γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
CNSphasing
HKL-2000data collection
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-11-25
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance