2F4Q

Crystal Structure of Deinococcus radiodurans topoisomerase IB


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structure of a bacterial type IB DNA topoisomerase reveals a preassembled active site in the absence of DNA.

Patel, A.Shuman, S.Mondragon, A.

(2006) J.Biol.Chem. 281: 6030-6037

  • DOI: 10.1074/jbc.M512332200

  • PubMed Abstract: 
  • Type IB DNA topoisomerases are found in all eukarya, two families of eukaryotic viruses (poxviruses and mimivirus), and many genera of bacteria. They alter DNA topology by cleaving and resealing one strand of duplex DNA via a covalent DNA-(3-phosphot ...

    Type IB DNA topoisomerases are found in all eukarya, two families of eukaryotic viruses (poxviruses and mimivirus), and many genera of bacteria. They alter DNA topology by cleaving and resealing one strand of duplex DNA via a covalent DNA-(3-phosphotyrosyl)-enzyme intermediate. Bacterial type IB enzymes were discovered recently and are described as poxvirus-like with respect to their small size, primary structures, and bipartite domain organization. Here we report the 1.75-A crystal structure of Deinococcus radiodurans topoisomerase IB (DraTopIB), a prototype of the bacterial clade. DraTopIB consists of an amino-terminal (N) beta-sheet domain (amino acids 1-90) and a predominantly alpha-helical carboxyl-terminal (C) domain (amino acids 91-346) that closely resemble the corresponding domains of vaccinia virus topoisomerase IB. The five amino acids of DraTopIB that comprise the catalytic pentad (Arg-137, Lys-174, Arg-239, Asn-280, and Tyr-289) are preassembled into the active site in the absence of DNA in a manner nearly identical to the pentad configuration in human topoisomerase I bound to DNA. This contrasts with the apoenzyme of vaccinia topoisomerase, in which three of the active site constituents are either displaced or disordered. The N and C domains of DraTopIB are splayed apart in an "open" conformation, in which the surface of the catalytic domain containing the active site is exposed for DNA binding. A comparison with the human topoisomerase I-DNA cocrystal structure suggests how viral and bacterial topoisomerase IB enzymes might bind DNA circumferentially via movement of the N domain into the major groove and clamping of a disordered loop of the C domain around the helix.


    Organizational Affiliation

    Department of Biochemistry, Molecular and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, IL 60208, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
type I topoisomerase, putative
A
346Deinococcus radiodurans (strain ATCC 13939 / DSM 20539 / JCM 16871 / LMG 4051 / NBRC 15346 / NCIMB 9279 / R1 / VKM B-1422)Mutation(s): 0 
Find proteins for Q9RWH8 (Deinococcus radiodurans (strain ATCC 13939 / DSM 20539 / JCM 16871 / LMG 4051 / NBRC 15346 / NCIMB 9279 / R1 / VKM B-1422))
Go to UniProtKB:  Q9RWH8
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.197 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 38.094α = 90.00
b = 64.966β = 91.78
c = 76.622γ = 90.00
Software Package:
Software NamePurpose
SHARPphasing
XDSdata scaling
REFMACrefinement
MAR345data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-12-27
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.3: 2017-10-18
    Type: Refinement description