3-D reconstructions of biological macromolecular complexes by electron microscopy

Friday, November 18, 2011 - 8:30am - 9:30am
Keller 3-180
Peter Doerschuk (Cornell University)
Single-particle cryo electron microscopy provides
images of biological macromolecular complexes with
spatial sampling on the order of 1-2 Angstrom.
Combining on the order of 100,000 such images can result
in 3-D reconstructions of the electron scattering
intensity of the complex with a spatial resolution as
fine as 4-5 Angstrom. Due to damage in the imaging
process, each complex is imaged only once and therefore
having a homogeneous ensemble of complexes is
important. Algorithms and results will be presented
for the case where the complexes are not homogeneous
and the reconstruction yields a statistical description
of the electron scattering intensity rather than a
single unique intensity. Related work on computed
electron tomography, where the electron scattering
intensity of individual complexes are determined but at
lower resolution will also be presented.