Award Abstract #0079441
Acquisition of a 300KeV FEG Energy-Filtered Liquid Helium-Stage Electron Microscope for Three-Dimensional Analysis of Supramolecular and Cellular Structures

NSF Org:	DBI Division of Biological Infrastructure
Initial Amendment Date:	August 1, 2000
Latest Amendment Date:	August 1, 2000
Award Number:	0079441
Award Instrument:	Standard Grant
Program Manager:	Helen G. Hansma DBI Division of Biological Infrastructure BIO Directorate for Biological Sciences
Start Date:	August 1, 2000
Expires:	July 31, 2002 (Estimated)
Awarded Amount to Date:	$1077035
Investigator(s):	David Agard agard@msg.ucsf.edu (Principal Investigator) John Sedat (Co-Principal Investigator)
Sponsor:	University of California-San Francisco 1855 Folsom St Ste 425 SAN FRANCISCO, CA 94103 415/476-2977
NSF Program(s):	MAJOR RESEARCH INSTRUMENTATION
Field Application(s):	0510301 Structure & Function
Program Reference Code(s):	BIOT, 9184
Program Element Code(s):	1189

ABSTRACT

A state-of-the-art Philips Tecnai F30 Helium Electron Microscope with an attached Gatan Imaging Energy Filter (GIF) and 2Kx2K CCD detector will be used for high-resolution biological imaging at both the atomic and cellular levels. Increasingly, the frontiers of cell biology focus on elucidating the control of cellular shape and organization, the nature and function of cellular organelles, and the role of complex protein machines. Such project areas also define a new frontier for structural biology where the goals are to determine not the structures of individual molecules, but structures of supramolecular complexes as large as entire cellular organelles. Embodied in this goal is a switch from the largely reductionist approach of the past to one that is, at its heart, integrative. Electron microscopy (EM) is uniquely poised to meet this challenge. Single particle reconstruction methods (SPR) hold the promise of near atomic resolution structures of very large complexes while Intermediate Voltage EM Tomography (EMT) provides the unique ability to integrate this information into the context of the whole cell.

The combination of Intermediate voltage (300kV) and Field Emission Gun provide optimal imaging for both thin and thick samples. Liquid helium cooling of the sample significantly reduces the effects of beam damage as well as the completely redesigned tilting stage provides unprecedented sample stability and freedom from drift. Addition of an imaging energy filter will revolutionize thick-section imaging and improve cryo imaging by removing inelastic electron scatter. The large area CCD will provide optimal on-line digital image recording. The result will be a facility unique in the US. Goals are to reach 25 angstrom resolution on EMT reconstruction of samples > 200nm thick and to reach 4-7 angstrom resolution from SPR of particles larger than 500 KDa. The combination of the capabilities of this microscope with automated data collection methods being developed, should enable near atomic resolution reconstruction of single macromolecular complexes to become a reality.

This instrumentation will empower major advances in cell biology and polymer science. A core user group of scientists from UCSF, Stanford, Berkeley, as well as the more distant Harvard and U. North Carolina has substantial tomography expertise and focuses on fundamentally important problems in biology and polymer science. Projects range from the understanding mechanisms controlling actin and microtubule cytoskeletal organization, the structure of chromosomes and mitotic spindle, the structure of the transcriptional initiation complex, the organization of the neuromuscular junction, and the guiding principles of organization in complex plastics.

The equipment will be in the existing Electron Microscope Laboratory in the UCSF Biochemistry Department and in August 2002 will be moved to the new Mission Bay campus. This facility is available to the entire campus as well as to outside users. A center for electron microscope tomography will act as a magnet to attract and train top students and postdocs. The UCSF programs in Biophysics and Cell Biology provide excellent opportunities for training graduate students and actively seek to attract minority students to campus.

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