Name: using tomoauto: a protocol for high-throughput automated cryo-electron tomography
Uploaded: 2016-01-30T15:00:00
Description: Watch this Scientific Journal Video about Using Tomoauto: A Protocol for High-throughput Automated Cryo-electron Tomography at JoVE.com

We thank Dr. William Margolin for comments. We are grateful for the support on SerialEM from Drs. David Mastronarde and Chen Xu. D.M., B.H. and J.L. were supported by Grant R01AI087946 from the National Institute of Allergy and Infectious Diseases, Grants R01GM110243 and R01GM107629 from the National Institute of General Medical Sciences (NIGMS), and Grant AU-1714 from the Welch Foundation. The direct electron detector was funded by National Institutes of Health Award S10OD016279.

1. Minicell Preparation
<ol>
	<li>To make S. flexneri minicells, transform 1 &#181;l of plasmid pBS58, which constitutively expresses Escherichia coli cell division genes ftsQ, ftsA, and ftsZ from a low-copy spectinomycin-resistant plasmid into 5 &#181;l electrocompetent Streptomycin-resistant serotype 5a (M90T-Sm) cells by electroporation at 2.5 kV for 5 msec in 1 mm cuvettes.</li>
	<li>Store minicell samples at -80 &#176;C in 15% glycerol in a 1.5 ml cryogenic microtube. When ready...

<ol>
	<li>Cornelis, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+type+III+secretion+injectisome.">The type III secretion injectisome.</a> Nat. Rev. Microbiol. 4 (11), 811-825 (2006).</li><li>Galan, J. E., Wolf-Watz, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+delivery+into+eukaryotic+cells+by+type+III+secretion+machines.">Protein delivery into eukaryotic cells by type III secretion machines.</a> Nature. 444 (7119), 567-573 (2006).</li><li>Kubori, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Supramolecular+structure+of+the+Salmonella+typhimurium+type+III+protein+secretion+system.">Supramolecular structure of the Salmonella typhimurium type III protein secretion system.</a> Science. 280 (5363), 602-605 (1998).</li><li>Schraidt, O., Marlovits, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+model+of+Salmonella's+needle+complex+at+subnanometer+resolution.">Three-dimensional model of Salmonella's needle complex at subnanometer resolution.</a> Science. 331 (6021), 1192-1195 (2011).</li><li>Hodgkinson, J. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+reconstruction+of+the+Shigella+T3SS+transmembrane+regions+reveals+12-fold+symmetry+and+novel+features+throughout.">Three-dimensional reconstruction of the Shigella T3SS transmembrane regions reveals 12-fold symmetry and novel features throughout.</a> Nat. Struct. Mol. Biol. 16 (5), 477-485 (2009).</li><li>Kudryashev, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+structural+analysis+of+the+Yersinia+enterocolitica+injectisome.">In situ structural analysis of the Yersinia enterocolitica injectisome.</a> eLife. 2, e00792 (2013).</li><li>Kawamoto, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Common+and+distinct+structural+features+of+Salmonella+injectisome+and+flagellar+basal+body.">Common and distinct structural features of Salmonella injectisome and flagellar basal body.</a> Scientific Reports. 3, 3369-3369 (2013).</li><li>Briggs, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+biology+in+situ-the+potential+of+subtomogram+averaging.">Structural biology in situ-the potential of subtomogram averaging.</a> Curr. Opin. Struct. Biol. 23 (2), 261-267 (2013).</li><li>Schur, F. K., Hagen, W. J., de Marco, A., Briggs, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+protein+structure+at+8.5&#197;+resolution+using+cryo-electron+tomography+and+sub-tomogram+averaging.">Determination of protein structure at 8.5&#197; resolution using cryo-electron tomography and sub-tomogram averaging.</a> J. Struct. Biol. 184 (3), 394-400 (2013).</li><li>Mastronarde, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+electron+microscope+tomography+using+robust+prediction+of+specimen+movements.">Automated electron microscope tomography using robust prediction of specimen movements.</a> J. Struct. Biol. 152 (1), 36-51 (2005).</li><li>Zheng, S. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=UCSF+tomography:+an+integrated+software+suite+for+real-time+electron+microscopic+tomographic+data+collection,+alignment+and+reconstruction.">UCSF tomography: an integrated software suite for real-time electron microscopic tomographic data collection, alignment and reconstruction.</a> J. Struct. Biol. 157 (1), 138-147 (2007).</li><li>Suloway, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fully+automated,+sequential+tilt-series+acquisition+with+Leginon.">Fully automated, sequential tilt-series acquisition with Leginon.</a> J. Struct. Biol. 167 (1), 11-18 (2009).</li><li>Kremer, J. R., Mastronarde, D. N., McIntosh, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computer+visualization+of+three-dimensional+image+data+using+IMOD.">Computer visualization of three-dimensional image data using IMOD.</a> J. Struct. Biol. 116 (1), 71-76 (1996).</li><li>Winkler, H., Taylor, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accurate+marker-free+alignment+with+simultaneous+geometry+determination+and+reconstruction+of+tilt-series+in+electron+tomography.">Accurate marker-free alignment with simultaneous geometry determination and reconstruction of tilt-series in electron tomography.</a> Ultramicroscopy. 106 (3), 240-254 (2006).</li><li>Winkler, H., Zhu, P., Liu, J., Ye, F., Roux, K. H., Taylor, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tomographic+subvolume+alignment+and+classification+applied+to+myosin+V+and+SIV+envelope+spikes.">Tomographic subvolume alignment and classification applied to myosin V and SIV envelope spikes.</a> J. Struct. Biol. 165 (2), 64-77 (2009).</li><li>Nicastro, D., Schwartz, C. L., Pierson, J., Gaudette, R., Porter, M. E., McIntosh, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Molecular+Architecture+of+Axonemes+Revealed+by+Cryoelectron+Tomography.">The Molecular Architecture of Axonemes Revealed by Cryoelectron Tomography.</a> Science. 313 (5789), 944-948 (2006).</li><li>Casta&#241;o-D&#237;ez, D., Kudryashev, M., Arheit, M., Stahlberg, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamo:+a+flexible,+user-friendly+development+tool+for+subtomogram+averaging+of+cryo-EM+data+in+high-performance+computing+environments.">Dynamo: a flexible, user-friendly development tool for subtomogram averaging of cryo-EM data in high-performance computing environments.</a> J. Struct. Biol. 178 (2), 139-151 (2012).</li><li>Hrabe, T., Chen, Y., Pfeffer, S., Cuellar, L. K., Mangold, A. V., F&#246;rster, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PyTom:+a+python-based+toolbox+for+localization+of+macromolecules+in+cryo-electron+tomograms+and+subtomogram+analysis.">PyTom: a python-based toolbox for localization of macromolecules in cryo-electron tomograms and subtomogram analysis.</a> J. Struct. Biol. 178 (2), 177-188 (2012).</li><li>Hu, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+of+the+type+III+secretion+sorting+platform+of+Shigella+flexneri.">Visualization of the type III secretion sorting platform of Shigella flexneri.</a> Proc. Natl. Acad. Sci. 112 (4), 1047-1052 (2015).</li><li>Iancu, C. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+cryotomography+sample+preparation+using+the+Vitrobot.">Electron cryotomography sample preparation using the Vitrobot.</a> Nat. Protoc. 1 (6), 2813-2819 (2007).</li><li>Chen, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+Cryoelectrontomography+of+Bacterial+Cells.">Electron Cryoelectrontomography of Bacterial Cells.</a> J. Vis. Exp. (39), e1943 (2010).</li><li>Li, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+counting+and+beam-induced+motion+correction+enable+near-atomic-resolution+single-particle+cryo-EM.">Electron counting and beam-induced motion correction enable near-atomic-resolution single-particle cryo-EM.</a> Nat. Methods. 10 (6), 584-590 (2013).</li><li>Xiong, Q., Morphew, M. K., Schwartz, C. L., Hoenger, A. H., Mastronarde, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CTF+determination+and+correction+for+low+dose+tomographic+tilt+series.">CTF determination and correction for low dose tomographic tilt series.</a> J. Struct. Biol. 168 (3), 378-387 (2009).</li><li>Amat, F., Moussavi, F., Comolli, L. R., Elidan, G., Downing, K. H., Horowitz, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Markov+random+field+based+automatic+image+alignment+for+electron+tomography.">Markov random field based automatic image alignment for electron tomography.</a> J. Struct. Biol. 161 (3), 260-275 (2008).</li><li>Rouhou, A., Grigorieff, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CTFFIND4:+Fast+and+accurate+defocus+estimation+from+electron+micrographs.">CTFFIND4: Fast and accurate defocus estimation from electron micrographs.</a> bioRxiv. , (2015).</li><li>Agulleiro, J. I., Fernandez, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tomo3D+2.0+&#8211;+Exploitation+of+Advanced+Vector+eXtensions+(AVX)+for+3D+reconstruction.">Tomo3D 2.0 &#8211; Exploitation of Advanced Vector eXtensions (AVX) for 3D reconstruction.</a> J. Struct. Biol. 189 (2), 147-152 (2015).</li><li>Zhao, X., Zhang, K., Boquoi, T., Hu, B., Motaleb, M. A., Miller, K., James, M., Charon, N. W., Manon, M. D., Norris, S. J., Li, C., Liu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cryo-Electron+Tomography+Reveals+the+Sequential+Assembly+of+Bacterial+Flagella+in+Borrelia+burgdorferi.">Cryo-Electron Tomography Reveals the Sequential Assembly of Bacterial Flagella in Borrelia burgdorferi.</a> Proc Natl Acad Sci U S A. 110 (35), 14390-14395 (2013).</li><li>Hu, B., Margolin, W., Molineux, I. J., Liu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Bacteriophage+T7+Virion+Undergoes+Extensive+Structural+Remodeling+during+infection.">The Bacteriophage T7 Virion Undergoes Extensive Structural Remodeling during infection.</a> Science. 339 (6119), 576-579 (2013).</li><li>Liu, J., Hu, B., Morado, D. R., Jani, S., Manson, M. D., Margolin, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=W:+Molecular+architecture+of+chemoreceptor+arrays+revealed+by+cryoelectron+tomography+of+Escherichia+coli+minicells.">W: Molecular architecture of chemoreceptor arrays revealed by cryoelectron tomography of Escherichia coli minicells.</a> Proc Natl Acad Sci USA. 109 (23), e1481-e1488 (2012).</li><li>Russo, C. J., Passmore, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+microscopy:+Ultrastable+gold+substrates+for+electron+cryomicroscopy.">Electron microscopy: Ultrastable gold substrates for electron cryomicroscopy.</a> Science. 346 (6215), 1377-1380 (2014).</li></ol>

The high-throughput method described here enabled us to process 1,917 cryo tilt-series and produce over 4,500 sub-tomograms of the intact S. flexneri injectisome19. The collected data led to the detailed characterization of in situ injectisome, including the cytoplasmic sorting complex. The method was also utilized to visualize several mutant cells with specific deletion of putative protein components, which helped elucidate the composition of the sorting platform of the injectisome....

Type III secretion systems (T3SS) are essential virulence determinants for many Gram-negative pathogens. The injectisome, also known as the needle complex, is the central T3SS machine required for direct translocation of effector proteins from the bacterium into eukaryotic host cells1, 2. The injectisome comprises an extracellular needle, a basal body, and a cytoplasmic complex also known as the sorting complex3. Previous studies have elucidated 3-D structures of purified injectisomes from Salmonella and Shigella, along with the atomic structures of major basal body proteins4, 5. Recent in situ structures of injectisomes from Salmonella, Shigella, and Yersinia were revealed by cryo-ET6, 7. However, the cytoplasmic complex, essential for effector selection and needle assembly, has not been visualized in those structures.
Cryo-ET is the most suitable technique for imaging molecular machinery at nanometer resolution within its native cellular context (in situ). Nevertheless, the achievable resolution by cryo-ET is limited by specimen thickness. To overcome the drawback, we imaged intact injectisomes in a virulent Shigella flexneri strain that was genetically modified to produce minicells thin enough for cryo-ET. Another limitation of cryo-ET is the sensitivity of the sample to the radiation induced by the electron beam, which very quickly destroys the high-resolution information in the sample. As a result, extremely low doses are used for individual tilt-images so that a suitable dose can be distributed amongst the full tilt-series. This greatly lowers the signal-to-noise ratio (SNR) in the final reconstruction, which makes it difficult to differentiate the structural features of the subject from the large amount of noise in the tomogram and limits the resolution that can be achieved by cryo-ET. Conventional image processing such as Fourier and real-space filters as well as down sampling can be used to increase contrast, but at the expense of filtering out much of the high-resolution information. Recently, sub-tomogram averaging has made it possible to greatly increase the SNR and subsequently the final resolution in some cases to sub-nanometer levels8, 9. A more detailed analysis of complexes is made possible by computationally extracting thousands of sub-tomograms containing the areas of interest from the original tomograms and then aligning and averaging the sub-tomograms to determine in situ complex structures with higher SNR and higher resolution. These methods can be integrated with genetic approaches to provide even greater insights into macromolecular assemblies and their dynamic conformations in the native cellular context.
In general, tens or even hundreds of thousand sub-tomograms need to be averaged in order to determine high-resolution structures in situ. The acquisition of a sufficient number of tilt-series needed to produce this large number of sub-tomograms quickly becomes a bottleneck. The resulting tilt-series are often affected by beam-induced shift, stage backlash, as well as magnification, rotation and skew defects, which must be solved to bring the tilt-series into alignment prior to reconstruction. The tilt series is typically aligned by tracking gold fiducial markers, which are traditionally selected manually through inspection of the tilt-series, causing yet another bottleneck. Many software packages have been developed for automated tilt-series acquisition through computer-controlled electron microscopes10, 11, 12, tilt-series alignment and reconstruction13, 14 and sub-tomogram averaging15-18. As these packages handle discrete operations in the workflow of cryo-ET, it becomes desirable to build a higher level of abstraction into the process to systematically streamline the entire scheme into a single pipeline. Therefore, we developed a software wrapper library &#34;tomoauto&#34; designed to organize a number of these packages into a single semi-automated unit, allowing for simple user operation while maintaining full configuration of each component in a centralized manner. The library is open-source, well documented, continually developed and freely available for use, tailored development or further integration by means of an online remote source code repository (http://github.com/DustinMorado/tomoauto).
This high-throughput cryo-ET pipeline has been utilized to visualize intact injectisomes in S. flexneri minicells. A total of 1,917 tomograms were generated using this method, revealing a high-resolution in situ structure of the intact machine including the cytoplasmic sorting platform determined by sub-tomogram averaging19. Together with molecular modeling of wild-type and mutant machines, our high-throughput pipeline provides a new avenue to understand the structure and function of the intact injectisome in the native cellular context.

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		<tr height="21">
			<td height="21" style="height:21px;width:160px;">Glycerol</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:116px;">G9012</td>
			<td style="width:164px;"></td>
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			<td height="21" style="height:21px;width:160px;">Tyrptic Soy Broth</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:116px;">22092</td>
			<td style="width:164px;"></td>
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			<td height="21" style="height:21px;width:160px;">Spectinomycin</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:116px;">S0692</td>
			<td style="width:164px;"></td>
		</tr>
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			<td height="42" style="height:42px;width:160px;">Electroporation Apparatus</td>
			<td style="width:211px;">Bio-rad</td>
			<td>165-2100</td>
			<td style="width:164px;"></td>
		</tr>
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			<td height="21" style="height:21px;width:160px;">1 mm Cuvette</td>
			<td style="width:211px;">BTX</td>
			<td>45-0124</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:160px;">1.5 mL Cryogenic Tube</td>
			<td style="width:211px;">Thermoscientific</td>
			<td>5000-1020</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">1.5 mL Microcentrifuge Tube</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td>Z336769</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:160px;">Holey Carbon Grids</td>
			<td style="width:211px;">Quantifoil 
			(Electron Microscopy Sciences)</td>
			<td style="width:116px;">Q2100CR2</td>
			<td style="width:164px;">R2/2 200 Cu</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Glow Discharge Device</td>
			<td style="width:211px;">In-House</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">Commercial Alternative Available</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Vacuum Desiccator</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:116px;">Z119016&#160;</td>
			<td style="width:164px;">Used in In-House Glow Discharge Device</td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:160px;">High-Frequency Generator</td>
			<td style="width:211px;">Electro-Technic Products</td>
			<td style="width:116px;">BD-10A</td>
			<td style="width:164px;">Used in In-House Glow Discharge Device.&#160; CAUTION: This device generates high voltages.</td>
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			<td height="21" style="height:21px;width:160px;">Centrifuge</td>
			<td style="width:211px;"></td>
			<td style="width:116px;"></td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:160px;">Forceps</td>
			<td style="width:211px;">Dumont 
			(Electron Microscopy Sciences)</td>
			<td style="width:116px;">72705-D</td>
			<td style="width:164px;">Style 5 Anti-magnetic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:160px;">Colliodal Gold</td>
			<td style="width:211px;">Aurion</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">BSA 10nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:160px;">Filter Paper</td>
			<td style="width:211px;">Whatman</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">#2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:160px;">Ethane&#160;</td>
			<td style="width:211px;">Matheson Tri-Gas</td>
			<td style="width:116px;">UN1035</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:160px;">Nitrogen</td>
			<td style="width:211px;">Matheson Tri-Gas</td>
			<td style="width:116px;">UN1977</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Plunger Device</td>
			<td style="width:211px;">In-House</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">Commercial Alternative Available</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Cryogenic Grid Storage Box</td>
			<td style="width:211px;">Electron Microscopy Sciences</td>
			<td style="width:116px;">71166-30</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Transmission Electron Microscope</td>
			<td style="width:211px;">FEI</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">Tecnai Polara F30 
			(300 KeV)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Direct Detection Device Camera</td>
			<td style="width:211px;">Gatan</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">K2 Summit</td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:160px;">Tomogram Acquisiton Software</td>
			<td style="width:211px;">SerialEM</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">http://bio3d.colorado.eud/SerialEM Alternatives: UCSF Tomography, Leginon, FEI Batch Tomography</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:160px;">Beam-induced Motion Correction Software</td>
			<td style="width:211px;">MOTIONCORR</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">http://cryoem.ucsf.edu/software/driftcorr.html Requires &#62;2GB Nvidia GPU</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:160px;">Tilt-Series Alignment Software</td>
			<td style="width:211px;">IMOD</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">http://bio3d.colorado.edu/IMOD Alternatives: XMIPP, Protomo</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:160px;">Automatic Fiducial Marker Modelling Software</td>
			<td style="width:211px;">IMOD</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">Alternatives: RAPTOR (Included in IMOD0 
			(Usable in tomoauto)</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:160px;">CTF Determination Software</td>
			<td style="width:211px;">IMOD</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">Alternatives: CTFFIND http://grigoriefflab.janelia.org/ctf 
			(Usable in tomoauto)</td>
		</tr>
		<tr height="147">
			<td height="147" style="height:147px;width:160px;">Tilt-Series Reconstruction Software</td>
			<td style="width:211px;">tomo3d</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">https://sites.google.com/site/3demimageprocessing/tomo3d Alternatives: IMOD, XMIPP http://xmipp.cnb.csic.es , Protomo</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:160px;">Tilt-Series Automated Processing Software</td>
			<td style="width:211px;">tomoauto</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">https://github.com/DustinMorado/tomoauto</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:160px;">Particle Picking Software</td>
			<td style="width:211px;">i3</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">http://www.electrontomography.org Alternatives: IMOD</td>
		</tr>
		<tr height="126">
			<td height="126" style="height:126px;width:160px;">Subvolume Averaging Software</td>
			<td style="width:211px;">i3</td>
			<td style="width:116px;"></td>
			<td style="width:164px;">Alternatives: PEET http://bio3d.colorado.edu/PEET, Dynamo https://dynamo.bioz.unibas.ch , PyTom http://pytom.org</td>
		</tr>
	</tbody>
</table>

using tomoauto: a protocol for high-throughput automated cryo-electron tomography

Cryo-electron tomography (Cryo-ET) is a powerful three-dimensional (3-D) imaging technique for visualizing macromolecular complexes in their native context at a molecular level. The technique involves initially preserving the sample in its native state by rapidly freezing the specimen in vitreous ice, then collecting a series of micrographs from different angles at high magnification, and finally computationally reconstructing a 3-D density map. The frozen-hydrated specimen is extremely sensitive to the electron beam and so micrographs are collected at very low electron doses to limit the radiation damage. As a result, the raw cryo-tomogram has a very low signal to noise ratio characterized by an intrinsically noisy image. To better visualize subjects of interest, conventional imaging analysis and sub-tomogram averaging in which sub-tomograms of the subject are extracted from the initial tomogram and aligned and averaged are utilized to improve both contrast and resolution. Large datasets of tilt-series are essential to understanding and resolving the complexes at different states, conditions, or mutations as well as obtaining a large enough collection of sub-tomograms for averaging and classification. Collecting and processing this data can be a major obstacle preventing further analysis. Here we describe a high-throughput cryo-ET protocol based on a computer-controlled 300kV cryo-electron microscope, a direct detection device (DDD) camera and a highly effective, semi-automated image-processing pipeline software wrapper library tomoauto developed in-house. This protocol has been effectively utilized to visualize the intact type III secretion system (T3SS) in Shigella flexneri minicells. It can be applicable to any project suitable for cryo-ET.

Samples of minicells S. flexneri were collected and processed as showed in the schematic Figure 1 using tomoauto following the pipeline detailed in Figure 2. Tilt-series were collected using SerialEM10, which allows for high-throughput tilt-series acquisition at points designated by the user on low-magnification montage maps (Figure 3). Micrographs were collected using dose-fractionation mode on a dire...

Watch this Scientific Journal Video about Using Tomoauto: A Protocol for High-throughput Automated Cryo-electron Tomography at JoVE.com

Using Tomoauto: A Protocol for High-throughput Automated Cryo-electron Tomography

We present a protocol on how to utilize high-throughput cryo-electron tomography to determine high resolution in situ structures of molecular machines. The protocol permits large amounts of data to be processed, avoids common bottlenecks and reduces resource downtime, allowing the user to focus on important biological questions.

Cryo-electron tomography (Cryo-ET) is a powerful three-dimensional (3-D) imaging technique for visualizing macromolecular complexes in their native ...

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