5CB1

Apo enzyme of human Polymerase lambda


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.230 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Mechanism for the Fidelity Modulation of DNA Polymerase lambda

Liu, M.S.Tsai, H.Y.Liu, X.X.Ho, M.C.Wu, W.J.Tsai, M.D.

(2016) J.Am.Chem.Soc. 138: 2389-2398

  • DOI: 10.1021/jacs.5b13368
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The mechanism of DNA polymerase (pol) fidelity is of fundamental importance in chemistry and biology. While high-fidelity pols have been well studied, much less is known about how some pols achieve medium or low fidelity with functional importance. H ...

    The mechanism of DNA polymerase (pol) fidelity is of fundamental importance in chemistry and biology. While high-fidelity pols have been well studied, much less is known about how some pols achieve medium or low fidelity with functional importance. Here we examine how human DNA polymerase λ (Pol λ) achieves medium fidelity by determining 12 crystal structures and performing pre-steady-state kinetic analyses. We showed that apo-Pol λ exists in the closed conformation, unprecedentedly with a preformed MgdNTP binding pocket, and binds MgdNTP readily in the active conformation in the absence of DNA. Since prebinding of MgdNTP could lead to very low fidelity as shown previously, it is attenuated in Pol λ by a hydrophobic core including Leu431, Ile492, and the Tyr505/Phe506 motif. We then predicted and demonstrated that L431A mutation enhances MgdNTP prebinding and lowers the fidelity. We also hypothesized that the MgdNTP-prebinding ability could stabilize a mismatched ternary complex and destabilize a matched ternary complex, and provided evidence with structures in both forms. Our results demonstrate that, while high-fidelity pols follow a common paradigm, Pol λ has developed specific conformations and mechanisms for its medium fidelity. Structural comparison with other pols also suggests that different pols likely utilize different conformational changes and microscopic mechanisms to achieve their catalytic functions with varying fidelities.


    Organizational Affiliation

    Institute of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase lambda
A, B
326Homo sapiensMutation(s): 0 
Gene Names: POLL
EC: 2.7.7.7, 4.2.99.-
Find proteins for Q9UGP5 (Homo sapiens)
Go to Gene View: POLL
Go to UniProtKB:  Q9UGP5
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.230 
  • Space Group: I 41 2 2
Unit Cell:
Length (Å)Angle (°)
a = 205.285α = 90.00
b = 205.285β = 90.00
c = 111.395γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data scaling
PDB_EXTRACTdata extraction
PHENIXrefinement
PHASERphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2015-06-30 
  • Released Date: 2016-02-24 
  • Deposition Author(s): Liu, M.S., Tsai, M.D.

Revision History 

  • Version 1.0: 2016-02-24
    Type: Initial release
  • Version 1.1: 2016-03-09
    Type: Database references