3cau
D7 symmetrized structure of unliganded GroEL at 4.2 Angstrom resolution by cryoEMD7 symmetrized structure of unliganded GroEL at 4.2 Angstrom resolution by cryoEM
Structural highlights
Function[CH60_ECOLI] Prevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions.[HAMAP-Rule:MF_00600] Essential for the growth of the bacteria and the assembly of several bacteriophages. Also plays a role in coupling between replication of the F plasmid and cell division of the cell.[HAMAP-Rule:MF_00600] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn 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. De novo backbone trace of GroEL from single particle electron cryomicroscopy.,Ludtke SJ, Baker ML, Chen DH, Song JL, Chuang DT, Chiu W Structure. 2008 Mar;16(3):441-8. PMID:18334219[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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