https://3demmethods.i2pc.es/index.php?action=history&feed=atom&title=1999Conway_Review 2026-05-24T19:52:42Z Revision history for this page on the wiki MediaWiki 1.44.2 https://3demmethods.i2pc.es/index.php?title=1999Conway_Review&diff=1788&oldid=prev 2009-04-22T08:41:27Z

<p></p> <p><b>New page</b></p><div>== Citation ==<br /> <br /> Conway JF, Steven AC (1999) Methods for reconstructing density<br /> maps of “single” particles from cryoelectron micrographs to subnanometer<br /> resolution. J Struct Biol 128:106–118<br /> <br /> [http://scholar.google.es/scholar?hl=en&amp;lr=&amp;cites=2335975119783036381 Cited by]<br /> <br /> == Abstract ==<br /> <br /> Recently the resolution attainable in density maps calculated from cryo-electron micrographs of free-standing virus capsids has advanced to resolutions below 1 nm. This represents a significant milestone in that resolutions of this order potentially allow direct visualization of individual elements of protein secondary structure (i.e., alpha-helices), in addition to the shapes and connectivity of subdomains. We describe here a computational strategy for structural analyses at this level of detail: its principal innovation is a procedure for correcting the contrast transfer function of the electron microscope. Also important is the practice of combining data from pairs of differently defocused micrographs to improve the signal-to-noise ratio of the images, thereby allowing more precise determinations of the particles&#039; orientations and origins and contributing to higher resolution reconstructions. These procedures proved instrumental in our analysis of the capsid of hepatitis B virus at 9-A resolution (Conway et al., 1997, Nature 386, 91-94). Finally, we discuss the prospects for achieving comparable resolutions for isolated macromolecular complexes with lower symmetry or no symmetry and for further extension of the resolution.<br /> <br /> == Keywords ==<br /> <br /> == Links ==<br /> <br /> Article http://www.ncbi.nlm.nih.gov/pubmed/10600565<br /> <br /> == Related software ==<br /> <br /> == Related methods ==<br /> <br /> == Comments ==</div>

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