200D | pdb_0000200d

STABLE LOOP IN THE CRYSTAL STRUCTURE OF THE INTERCALATED FOUR-STRANDED CYTOSINE-RICH METAZOAN TELOMERE

• PDB DOI: https://doi.org/10.2210/pdb200D/pdb
• NAKB: 200D

• Classification: DNA
• Mutation(s): No 


• Deposited: 1995-02-16 Released: 1995-07-31 
• Deposition Author(s): Kang, C., Berger, I., Lockshin, C., Ratliff, R., Moyzis, R., Rich, A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.85 Å
• R-Value Free: 
  0.223 (Depositor) 
• R-Value Work: 
  0.190 (Depositor) 
• R-Value Observed: 
  0.190 (Depositor) 

Literature

Stable loop in the crystal structure of the intercalated four-stranded cytosine-rich metazoan telomere.

Kang, C., Berger, I., Lockshin, C., Ratliff, R., Moyzis, R., Rich, A.

(1995) Proc Natl Acad Sci U S A 92: 3874-3878

• PubMed: 7731999 
• DOI: https://doi.org/10.1073/pnas.92.9.3874
• Primary Citation Related Structures: 
  200D


• PubMed Abstract: 
  

  In most metazoans, the telomeric cytosine-rich strand repeating sequence is d(TAACCC). The crystal structure of this sequence was solved to 1.9-A resolution. Four strands associate via the cytosine-containing parts to form a four-stranded intercalated structure held together by C.C+ hydrogen bonds. The base-paired strands are parallel to each other, and the two duplexes are intercalated into each other in opposite orientations. One TAA end forms a highly stabilized loop with the 5' thymine Hoogsteen-base-paired to the third adenine. The 5' end of this loop is in close proximity to the 3' end of one of the other intercalated cytosine strands. Instead of being entirely in a DNA duplex, this structure suggests the possibility of an alternative conformation for the cytosine-rich telomere strands.

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Organizational Affiliation: 
• Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.

Biological Assembly 1  

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 3.51 kDa 
• Atom Count: 258 
• Modeled Residue Count: 12 
• Deposited Residue Count: 12 
• Unique nucleic acid chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Length	Organism	Image
DNA (5'-D(*TP*AP*AP*CP*CP*C)-3')	A, B	6	N/A

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.85 Å
• R-Value Free:  0.223 (Depositor) 
• R-Value Work:  0.190 (Depositor) 
• R-Value Observed: 0.190 (Depositor) 

Space Group: F 2 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 59.94	α = 90
b = 81.33	β = 90
c = 26.86	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	refinement
MSC	data reduction

Structure Validation

Entry History 

Deposition Data

• Released Date: 1995-07-31 
Deposition Author(s): Kang, C., Berger, I., Lockshin, C., Ratliff, R., Moyzis, R., Rich, A.

Revision History  

• Version 1.0: 1995-07-31
  Type: Initial release
  
• Version 1.1: 2008-05-22
  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