Briggs JAG. Structural biology in situ--the potential of subtomogram averaging.
Curr Opin Struct Biol 2013;
23:261-7. [PMID:
23466038 DOI:
10.1016/j.sbi.2013.02.003]
[Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/12/2013] [Accepted: 02/13/2013] [Indexed: 12/27/2022]
Abstract
Cryo-electron tomography provides low-resolution 3D views of cells, organelles, or viruses. Macromolecular complexes present in multiple copies can be subsequently identified within the 3D reconstruction (the tomogram), computationally extracted, and averaged to obtain higher resolution 3D structures, as well as a map of their spatial distribution. This method, called subtomogram averaging or subvolume averaging, allows structures of macromolecular complexes to be resolved in situ. Recent applications have provided in situ structural data at resolutions of 2-4 nm on samples including polysomes, nuclear pores, vesicle coats, and viral surface proteins. Here I describe the method and discuss limitations, advances and recent applications. I speculate how the method will solve more structures at higher resolution, allowing in situ structural biology.
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