3J7H

Structure of beta-galactosidase at 3.2-A resolution obtained by cryo-electron microscopy


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.2 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structure of beta-galactosidase at 3.2- angstrom resolution obtained by cryo-electron microscopy.

Bartesaghi, A.Matthies, D.Banerjee, S.Merk, A.Subramaniam, S.

(2014) Proc.Natl.Acad.Sci.USA 111: 11709-11714

  • DOI: 10.1073/pnas.1402809111

  • PubMed Abstract: 
  • We report the solution structure of Escherichia coli β-galactosidase (∼465 kDa), solved at ∼3.2-Å resolution by using single-particle cryo-electron microscopy (cryo-EM). Densities for most side chains, including those of residues in the active site, ...

    We report the solution structure of Escherichia coli β-galactosidase (∼465 kDa), solved at ∼3.2-Å resolution by using single-particle cryo-electron microscopy (cryo-EM). Densities for most side chains, including those of residues in the active site, and a catalytic Mg(2+) ion can be discerned in the map obtained by cryo-EM. The atomic model derived from our cryo-EM analysis closely matches the 1.7-Å crystal structure with a global rmsd of ∼0.66 Å. There are significant local differences throughout the protein, with clear evidence for conformational changes resulting from contact zones in the crystal lattice. Inspection of the map reveals that although densities for residues with positively charged and neutral side chains are well resolved, systematically weaker densities are observed for residues with negatively charged side chains. We show that the weaker densities for negatively charged residues arise from their greater sensitivity to radiation damage from electron irradiation as determined by comparison of density maps obtained by using electron doses ranging from 10 to 30 e(-)/Å(2). In summary, we establish that it is feasible to use cryo-EM to determine near-atomic resolution structures of protein complexes (<500 kDa) with low symmetry, and that the residue-specific radiation damage that occurs with increasing electron dose can be monitored by using dose fractionation tools available with direct electron detector technology.


    Organizational Affiliation

    Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Beta-galactosidase
A, B, C, D
1024Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: lacZ
EC: 3.2.1.23
Find proteins for P00722 (Escherichia coli (strain K12))
Go to UniProtKB:  P00722
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C, D
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.2 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-07-30
    Type: Initial release
  • Version 1.1: 2014-08-13
    Type: Database references
  • Version 1.2: 2014-08-27
    Type: Database references
  • Version 1.3: 2018-07-18
    Type: Data collection