2AE9

Solution Structure of the theta subunit of DNA polymerase III from E. coli


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Nuclear Magnetic Resonance Solution Structure of the Escherichia coli DNA Polymerase III {theta} Subunit.

Mueller, G.A.Kirby, T.W.Derose, E.F.Li, D.Schaaper, R.M.London, R.E.

(2005) J Bacteriol 187: 7081-7089

  • DOI: 10.1128/JB.187.20.7081-7089.2005
  • Primary Citation of Related Structures:  
    2AE9

  • PubMed Abstract: 
  • The catalytic core of Escherichia coli DNA polymerase III holoenzyme contains three subunits: alpha, epsilon, and theta. The alpha subunit contains the polymerase, and the epsilon subunit contains the exonucleolytic proofreading function. The small ( ...

    The catalytic core of Escherichia coli DNA polymerase III holoenzyme contains three subunits: alpha, epsilon, and theta. The alpha subunit contains the polymerase, and the epsilon subunit contains the exonucleolytic proofreading function. The small (8-kDa) theta subunit binds only to epsilon. Its function is not well understood, although it was shown to exert a small stabilizing effect on the epsilon proofreading function. In order to help elucidate its function, we undertook a determination of its solution structure. In aqueous solution, theta yielded poor-quality nuclear magnetic resonance spectra, presumably due to conformational exchange and/or protein aggregation. Based on our recently determined structure of the theta homolog from bacteriophage P1, named HOT, we constructed a homology model of theta. This model suggested that the unfavorable behavior of theta might arise from exposed hydrophobic residues, particularly toward the end of alpha-helix 3. In gel filtration studies, theta elutes later than expected, indicating that aggregation is potentially responsible for these problems. To address this issue, we recorded 1H-15N heteronuclear single quantum correlation (HSQC) spectra in water-alcohol mixed solvents and observed substantially improved dispersion and uniformity of peak intensities, facilitating a structural determination under these conditions. The structure of theta in 60/40 (vol/vol) water-methanol is similar to that of HOT but differs significantly from a previously reported theta structure. The new theta structure is expected to provide additional insight into its physiological role and its effect on the epsilon proofreading subunit.


    Organizational Affiliation

    Laboratory of Structural Biology, MR-01, National Institute of Environmental Health Sciences, 111 Alexander Drive, Research Triangle Park, North Carolina 27709, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DNA polymerase III, theta subunitA76Escherichia coliMutation(s): 0 
Gene Names: holE
EC: 2.7.7.7
Find proteins for P0ABS8 (Escherichia coli (strain K12))
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Go to UniProtKB:  P0ABS8
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 
  • OLDERADO: 2AE9 Olderado

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-10-18
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance