Qiu-Xing Jiang, Ph.D. - US grants

Abstract The Southeastern Center for Microscopy of MacroMolecular Machines (SECM4) is a consortium of 15 Universities/Medical Centers with a total of 19 investigators throughout the Eastern United States studying a wide range of important biomedical projects as variable as high resolution virus structure, membrane protein structure, macromolecular complexes of various types, some isolated in active form from cells, bacterial ultrastructure, muscle filaments, spliceosomes, ribosomes complexes all of which will benefit from ready access to a high resolution electron microscope such as a Titan Krios equipped with a direct electron detector (DED). Human health implications extend from virus and bacterial pathogens to the understanding of diseases resulting form genetic mutations. The basic biology of cancer and heart disease is being studied in several member laboratories. The Titan Krios at Florida State University has been in operation since 2009 and recently has had its image recording device upgraded from CCD camera to a Direct Electron LLC, DE-20 direct electron detector positioned ahead of an existing imaging filter which removes inelastically scattered electrons thereby improving the image quality. Although we propose a robust plan to enable members to come to Florida State University, we propose creating a facility based on the synchrotron template currently in use at multiple sites X-ray crystallography beam lines around the country whereby users ship specimens to us and watch the data being collected as it comes off the microscope from the familiar confines of their own laboratories. We will provide sufficient preprocessing that consortium members can evaluate the prospects for obtaining a final high resolution structure from damage and motion corrected ?movie? images of their samples. The result will be a model for high throughput structure determination utilizing high-end instrumentation that can reveal the inner workings of complex macromolecules and subcellular structures.

ABSTRACT The Southeastern Consortium for Microscopy of MacroMolecular Machines (SECM4) comprises 10 Universities/Medical Centers throughout the Eastern United States with a total of 13 cryoEM investigators studying a wide range of important biomedical problems as variable as high resolution virus structure, membrane protein structure, macromolecu- lar complexes of various types, some isolated in active form from cells, bacterial ultrastructure, spliceosomes, ribosome complexes all of which benefit from access to Florida State Universities (FSU) Titan Krios and its DE-64 direct electron detector. Recently the FSU Titan Krios was upgraded through the addition of a FEI Volta phase plate and a Gatan BioQuantum/K3 imaging filter which facilitate imaging of small molecules using single particle methods as well as thicker specimens that are imaged using cryoelectron tomography. The upgrades expanded the range of medically related structural biology problems to which SECM4 members can contribute. These upgrades also have made the FSU Titan Krios, which was one of the earliest ones installed in the US, comparable to recently installed Titan Krios microscopes, except for one feature. Newer Titan Krios microscopes have a more robust Autoloader than the early version currently operating on The FSU microscope. The Autoloader is the device that facilitates exchange of frozen hydrated specimens from the outside world into the high, contamination free environment of the Titan Krios. The current Autoloader, installed in August 2011, is currently responsible for more than 50% of the operational down time due to instrument failure. This Administrative Supplement seeks funds to replace the current Autoloader with the most recent version with the goal of reducing the greatest cause of instrument down time. SECM4 operates on the synchrotron template currently in use at sites having X-ray crystallography beam lines around the country. SECM4 members ship specimens to FSU and watch the data being collected as it comes off the microscope from the familiar confines of their own laboratories. SECM4 provides sufficient preprocessing that consortium members can evaluate the prospects for obtaining a final high-resolution structure from damage and motion corrected ?movie? images of their samples. SECM4 will become a model for high throughput structure determination utilizing high-end instrumentation to reveal the inner workings of complex macromolecules and subcellular structures.

PROJECT SUMMARY Recently, single particle cryo-electron microscopy (cryo-EM) combined with 3-D reconstruction has emerged as a revolutionary tool for solving high-resolution 3-D structures of viruses and macromolecular complexes. The rapidly increasing number of near-atomic resolution (3-4?) structures solved using cryo-EM has allowed unprecedented atomic level understanding of fundamental cellular processes and viral infections. To obtain near-atomic resolution cryo-EM structures, requires the collection of high-resolution image data using state-of- the-art imaging resources, including both a high-end transmission electron microscope and a direct electron detector. The direct electron detectors not only improve image resolution and contrast, but also record movies for subsequent computational correction of electron beam-induced, sample movements during exposure. The increased image contrast and resolution are essential for solving near-atomic resolution structures of small protein complexes. However, the high cost to purchase and maintain a state-of-the-art cryo-EM resource, with both a high-end electron microscope and a direct electron detector, precludes many cryo-EM investigators from having access to these new techniques. Here, the creation of a Midwest Consortium for High- Resolution Cryo-electron Microscopy is proposed to provide access to such high-resolution data collection capability for cryo-EM laboratories without access to such resources. This consortium will consist of 4 investigators from the host institution (Purdue Univ.) which will maintain the high-resolution data collection resource (Titan Krios 300kV FEG microscope with phase plate, energy filter, and direct electron detector) and will provide services to 11 investigators from 10 partnering institutions (Boston Univ. School of Medicine, Michigan State Univ., Penn State College of Medicine, Rutgers Univ., Univ. of Alabama at Birmingham, Univ. of Colorado Boulder, Univ. of Kansas, Univ. of Missouri, Univ. of Vermont, and Virginia Commonwealth Univ.). The collective experience of the Purdue facility staff, faculty and onsite service engineer, in high-resolution cryo-EM imaging, will ensure that the facility operates at peak performance with minimal service interruptions. The high-resolution data collection capabilities established at Purdue and accessible to the partnering labs, will allow these investigators, who are all, except for the 3 new investigators, NIH-funded, to overcome the resolution barrier and facilitate discovery within their own cryo-EM projects on a range of structures, such as, bacterial pathogen adhesion proteins, human viruses, Huntington's Disease proteins, synaptic vesicle proteins, chemoreceptor signaling complex, etc. The Consortium will provide comprehensive support to the cryo-EM projects, including shipping samples, preparing sample grids, collecting high-resolution single particle and tomography images, processing raw movies, and transferring data back to the partners' labs. The data collection services will range from full data collection where partners simply mail in the samples and then receive the image data, to hands-on operations of the cryo-EM by partners trained by the host facility's staff.