1EH8

BENZYLATED HUMAN O6-ALKYLGUANINE-DNA ALKYLTRANSFERASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Active and alkylated human AGT structures: a novel zinc site, inhibitor and extrahelical base binding.

Daniels, D.S.Mol, C.D.Arvai, A.S.Kanugula, S.Pegg, A.E.Tainer, J.A.

(2000) EMBO J. 19: 1719-1730

  • DOI: 10.1093/emboj/19.7.1719
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Human O(6)-alkylguanine-DNA alkyltransferase (AGT), which directly reverses endogenous alkylation at the O(6)-position of guanine, confers resistance to alkylation chemotherapies and is therefore an active anticancer drug target. Crystal structures o ...

    Human O(6)-alkylguanine-DNA alkyltransferase (AGT), which directly reverses endogenous alkylation at the O(6)-position of guanine, confers resistance to alkylation chemotherapies and is therefore an active anticancer drug target. Crystal structures of active human AGT and its biologically and therapeutically relevant methylated and benzylated product complexes reveal an unexpected zinc-stabilized helical bridge joining a two-domain alpha/beta structure. An asparagine hinge couples the active site motif to a helix-turn-helix (HTH) motif implicated in DNA binding. The reactive cysteine environment, its position within a groove adjacent to the alkyl-binding cavity and mutational analyses characterize DNA-damage recognition and inhibitor specificity, support a structure-based dealkylation mechanism and suggest a molecular basis for destabilization of the alkylated protein. These results support damaged nucleotide flipping facilitated by an arginine finger within the HTH motif to stabilize the extrahelical O(6)-alkylguanine without the protein conformational change originally proposed from the empty Ada structure. Cysteine alkylation sterically shifts the HTH recognition helix to evidently mechanistically couple release of repaired DNA to an opening of the protein fold to promote the biological turnover of the alkylated protein.


    Organizational Affiliation

    The Skaggs Institute for Chemical Biology, Department of Molecular Biology, MB-4, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037-1027, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
O6-ALKYLGUANINE-DNA ALKYLTRANSFERASE
A
207Homo sapiensMutation(s): 0 
Gene Names: MGMT
EC: 2.1.1.63
Find proteins for P16455 (Homo sapiens)
Go to Gene View: MGMT
Go to UniProtKB:  P16455
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
BCS
Query on BCS
A
L-PEPTIDE LINKINGC10 H13 N O2 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.194 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 71.598α = 90.00
b = 71.598β = 90.00
c = 76.038γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
CNSphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-04-12
    Type: Initial release
  • Version 1.1: 2007-10-16
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance