Electron cryomicroscopy of single particles at subnanometer resolution.
Electron cryomicroscopy and single-particle reconstruction have advanced substantially over the past two decades. There are now numerous examples of structures that have been solved using this technique to better than 10 A resolution. At such resolutions, direct identification of alpha helices is possible and, often, beta-sheet-containing regions can be identified. The most numerous subnanometer resolution structures are the icosahedral viruses, as higher resolution is easier to achieve with higher symmetry. Important non-icosahedral structures solved to subnanometer resolution include several ribosome structures, clathrin assemblies and, most recently, the Ca2+ release channel. There is now hope that, in the next few years, this technique will achieve resolutions approaching 4 A, permitting a complete trace of the protein backbone without reference to a crystal structure.
Jiang
Wen
W
National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Ludtke
Steven J
SJ
D000818:Animals; D018834:Chaperonin 60 / Q000737:chemistry / Q000648:ultrastructure; D002966:Clathrin / Q000737:chemistry / Q000648:ultrastructure; D020285:Cryoelectron Microscopy / Q000379:methods*; D006801:Humans; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D012270:Ribosomes / Q000737:chemistry / Q000648:ultrastructure; D019837:Ryanodine Receptor Calcium Release Channel / Q000737:chemistry; D014764:Viral Proteins / Q000737:chemistry; D014780:Viruses / Q000737:chemistry / Q000648:ultrastructure
D018834:Chaperonin 60; D002966:Clathrin; D019837:Ryanodine Receptor Calcium Release Channel; D014764:Viral Proteins