2ynj | pdb_00002ynj
GroEL at sub-nanometer resolution by Constrained Single Particle Tomography
Structural highlights
Function[CH60_ECOUT] Prevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions (By similarity). Publication Abstract from PubMedCryo-electron microscopy (cryo-EM) is a powerful technique for 3D structure determination of protein complexes by averaging information from individual molecular images. The resolutions that can be achieved with single-particle cryo-EM are frequently limited by inaccuracies in assigning molecular orientations based solely on 2D projection images. Tomographic data collection schemes, however, provide powerful constraints that can be used to more accurately determine molecular orientations necessary for 3D reconstruction. Here, we propose "constrained single-particle tomography" as a general strategy for 3D structure determination in cryo-EM. A key component of our approach is the effective use of images recorded in tilt series to extract high-resolution information and correct for the contrast transfer function. By incorporating geometric constraints into the refinement to improve orientational accuracy of images, we reduce model bias and overrefinement artifacts and demonstrate that protein structures can be determined at resolutions of approximately 8 A starting from low-dose tomographic tilt series. Protein secondary structure determination by constrained single-particle cryo-electron tomography.,Bartesaghi A, Lecumberry F, Sapiro G, Subramaniam S Structure. 2012 Dec 5;20(12):2003-13. doi: 10.1016/j.str.2012.10.016. PMID:23217682[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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