Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 26.09 kDa 
• Atom Count: 2,049 
• Modelled Residue Count: 221 
• Deposited Residue Count: 223 
• Unique protein chains: 1

 1OIS

YEAST DNA TOPOISOMERASE I, N-TERMINAL FRAGMENT

• PDB DOI:  https://doi.org/10.2210/pdb1OIS/pdb

• Classification: DNA BINDING PROTEIN
• Organism(s): Saccharomyces cerevisiae
• Expression System: Saccharomyces cerevisiae
• Mutation(s): No 


• Deposited: 1996-09-14 Released: 1997-03-12 
• Deposition Author(s): Lue, N., Sharma, A., Mondragon, A., Wang, J.C.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.290 
• R-Value Work: 0.222 
• R-Value Observed: 0.222 

Literature

A 26 kDa yeast DNA topoisomerase I fragment: crystallographic structure and mechanistic implications.

Lue, N., Sharma, A., Mondragon, A., Wang, J.C.

(1995) Structure 3: 1315-1322

• PubMed: 8747458 
• DOI: https://doi.org/10.1016/s0969-2126(01)00269-6
• Primary Citation of Related Structures:  
  1OIS


• PubMed Abstract: 
  

Type I DNA topoisomerases, divided mechanistically into two subfamilies, are ubiquitous enzymes that participate in replication and transcription. In addition to its role in these fundamental processes, the biological importance of eukaryotic DNA topoisomerase I is underscored by its identification as the target of the antitumor alkaloid camptothecin. An understanding of the mechanism of catalysis and interactions with camptothecin and other drugs has been hampered by a lack of detailed structural information.

---

Organizational Affiliation: 

Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
DNA TOPOISOMERASE I	A	223	Saccharomyces cerevisiae	Mutation(s): 0  Gene Names: TOP1 EC: 5.99.1.2 (PDB Primary Data), 5.6.2.1 (UniProt)
UniProt
Find proteins for P04786 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c)) Explore P04786  Go to UniProtKB:  P04786

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.290 
• R-Value Work: 0.222 
• R-Value Observed: 0.222 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 47.2	α = 90
b = 53.07	β = 90
c = 116.89	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
DENZO	data reduction
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1997-03-12 
Deposition Author(s): Lue, N., Sharma, A., Mondragon, A., Wang, J.C.

Revision History  

• Version 1.0: 1997-03-12
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance