3CAU

D7 symmetrized structure of unliganded GroEL at 4.2 Angstrom resolution by cryoEM

Summary for 3CAU

• Entry DOI: 10.2210/pdb3cau/pdb
• Related: 3C9V
• EMDB information: 5001
• Descriptor: 60 kDa chaperonin (1 entity in total)
• Functional Keywords: groel, atp-binding, cell cycle, cell division, chaperone, nucleotide-binding, phosphoprotein
• Biological source: Escherichia coli
• Cellular location: Cytoplasm : P0A6F5
• Total number of polymer chains: 14
• Total formula weight: 774636.58

Authors

Ludtke, S.J.,Baker, M.L.,Chen, D.H.,Song, J.L.,Chuang, D.,Chiu, W. (deposition date: 2008-02-20, release date: 2008-09-02, Last modification date: 2024-02-21)

Primary citation

Ludtke, S.J.,Baker, M.L.,Chen, D.H.,Song, J.L.,Chuang, D.T.,Chiu, W.
De Novo Backbone Trace of GroEL from Single Particle Electron Cryomicroscopy.
Structure, 16:441-448, 2008

PubMed Abstract: In this work, we employ single-particle electron cryo-microscopy (cryo-EM) to reconstruct GroEL to approximately 4 A resolution with both D7 and C7 symmetry. Using a newly developed skeletonization algorithm and secondary structure element identification in combination with sequence-based secondary structure prediction, we demonstrate that it is possible to achieve a de novo Calpha trace directly from a cryo-EM reconstruction. The topology of our backbone trace is completely accurate, though subtle alterations illustrate significant differences from existing crystal structures. In the map with C7 symmetry, the seven monomers in each ring are identical; however, the subunits have a subtly different structure in each ring, particularly in the equatorial domain. These differences include an asymmetric salt bridge, density in the nucleotide-binding pocket of only one ring, and small shifts in alpha helix positions. This asymmetric conformation is different from previous asymmetric structures, including GroES-bound GroEL, and may represent a "primed state" in the chaperonin pathway.

PubMed: 18334219
DOI: 10.1016/j.str.2008.02.007

Experimental method

ELECTRON MICROSCOPY (4.2 Å)