Here we report a novel assay to visualize pili by light microscopy that led to the purification of CAULOBACTER: pili and the isolation of a cluster of seven genes, including the major pilin subunit gene pilA. In wild-type cells, ATP hydrolysis opens the SMC dimer, freeing one chromosome to segregate to the opposite pole. View details for DOI 10.1007/978-1-61779-282-3_8, View details for Web of Science ID 000305505504226, View details for Web of Science ID 000305505503547. Analysis of Dra I restriction fragments of DNA taken at various times from synchronized cell cultures labeled with 2'-deoxy[3H]guanosine has allowed us to determine the origin of DNA replication, the rate and direction of fork movement, and the order of gene replication. To define the mechanisms that mediate this temporal and spatial control, fla genes whose products are not known were accessed by the insertion of transposon-carried drug resistance markers. Here, we present a microscopy-based screen through which we discovered two FtsZ-binding proteins, FzlA and FzlC. Next to this is the third region, which is approximately 60 nm in length. Many recent studies have revealed exquisite subcellular localization of proteins, DNA, and other molecules within bacterial cells, giving credence to the concept of prokaryotic anatomy. Ph.D. Student, Medical Engineering, Defended 2020 A., Britos, L., Shapiro, L. A spindle-like apparatus guides bacterial chromosome segregation. We show that the cell-cycle timing of CcrM is critical for Caulobacter fitness. The Caulobacter ffs gene was shown to be functionally comparable to the Escherichia coli ffs gene by complementation. Postdoctoral Fellowship, Chemical Engineering, Caltech B.S. RNA polymerase-binding studies with restriction fragments of the rRNA gene cluster revealed three regions which bound enzyme, and these regions were shown to contain transcription initiation sites. Contreras, I., Bender, R. A., MANSOUR, J., Henry, S., Shapiro, L. In situ immunoassays for translation products. Biology & Geobiology, expected 2025 B., Melfi, M. D., Luong, K., Clark, T. A., Boitano, M., Wang, S., Zhou, B., Gonzalez, D., Collier, J., Turner, S. W., Korlach, J., Shapiro, L., McAdams, H. H. Oligomerization and higher-order assembly contribute to sub-cellular localization of a bacterial scaffold. B.S. x@caltech.edu, x=msoufi, Margaret Swift In mammals, genes from the same organism are similar only in the second parameter, because GC content varies widely among isochores. DipM localized to the division site in an FtsZ-dependent manner via its PG-binding LysM domains. Partitioning of the bacterial chromosome thus takes place while DNA replication is in progress. Quantitative Multicolor Subdiffraction Imaging of Bacterial Protein Ultrastructures in Three Dimensions. Small noncoding regulatory RNAs (sRNAs) play a key role in the posttranscriptional regulation of many bacterial genes. Deletion analysis indicated that a 55 bp DNA fragment was sufficient for normal, temporally regulated promoter activity. Prior growth on glucose results in a delay in enzyme expression and cell cycle arrest at the nonmotile, predivisional stage. Caltech-MIT-IBS Global Pioneer Fellow We report the design and application of HaloTag-based target-specific azido DCDHFs, a class of photoactivatable push-pull fluorogens which produce bright fluorescent labels suitable for single-molecule superresolution imaging in live bacterial and fixed mammalian cells. Cell division, essential for the viability of the organism, is dependent on the irreversible differentiation of a flagellated swarmer cell to a mature stalked cell. Currently: Assistant Professor of Biomedical Sciences View details for DOI 10.1073/pnas.1114444108. Complementing clones restore both motility and normal cell division. x@caltech.edu, x=sshivaei, Cameron Ashley Brandon Smith, PhD Regulated proteolysis is essential for cell cycle progression in both prokaryotes and eukaryotes. An impressively diverse array of mechanisms underlies bacterial polarity, including oscillatory systems, phospho-signaling pathways, the sensing of membrane curvature, and the integration of cell cycle regulators with polar maturation. These results are consistent with a model in which unreplicated DNA is pulled into the replication factory and newly replicated DNA is bidirectionally extruded from the complex, perhaps contributing to chromosome segregation. To determine when during the cell cycle the cytoplasm is compartmentalized so that cytoplasmic proteins can no longer diffuse between the two nascent progeny cell compartments, we designed a fluorescence loss in photobleaching assay. The flagellar promoters accessed by Tn5-VB32 exhibited temporal regulation analogous to the known flagellar and chemotaxis gene products. The requirement for an IHF binding site and an ftr-enhancer element in spatially transcribed flagellar promoters indicates that a common mechanism may be responsible for both temporal and polar transcription. Ph.D. Student, Neurobiology FtsZ is an essential bacterial GTPase that polymerizes at midcell, recruits the division machinery, and may generate constrictive forces necessary for cytokinesis. Here we demonstrate live-cell 3D superresolution imaging of Crescentin-eYFP, a cytoskeletal fluorescent protein fusion, colocalized with the surface of the bacterium Caulobacter crescentus using a double-helix point spread function microscope. Differential translation of operon-encoded genes facilitates precise cell cycle-timing for the dynamic assembly of multiprotein complexes, such as the flagellum and the stalk and the correct positioning of regulatory proteins to specific cell poles. Research Assistant Isamar Sanchez has been accepted into multiple Schools of Veterinary Medicine, and will be starting her DVM studies at Texas A&M in August! B.S. x@caltech.edu, x=mikhail, Scientists, Postdoc Scholars & Graduate Students Amemiya, K., Bellofatto, V., Shapiro, L., Feingold, J. Taken together, these results suggest that the activity of both ClpXP and ClpAP on divisome substrates is differentially regulated in daughter cells. The analysis of small predivisional vesicles showed that the MCP content is higher in the flagellated vesicles, and analysis of large flagellated vesicles showed that the MCPs are positioned preferentially in the swarmer cell portion of the predivisional cell. Both promoters were heat shock inducible, with maximal expression 10 to 20 min after heat shock. DEOXYRIBONUCLEIC-ACID SEQUENCE HOMOLOGIES AMONG BACTERIAL INSERTION SEQUENCE ELEMENTS AND GENOMES OF VARIOUS ORGANISMS, CELL-CYCLE-ASSOCIATED REARRANGEMENT OF INVERTED REPEAT DNA-SEQUENCES. Electronics and Electrical Engineering, Manipal University Leonard, K. R., Kleinschmidt, A. K., Agabian-Keshishian, N., Shapiro, L., MAIZEL, J. V. CHARACTERIZATION OF A PROTEIN ACYL KINASE FROM CAULOBACTER-CRESCENTUS, STRUCTURAL STUDIES ON CAPSID OF CAULOBACTER-CRESCENTUS BACTERIOPHAGE PHICBK. x@caltech.edu, x=thamza, Bella Hurvitz Herrmann, J., Comerci, C. J., Jabbarpour, F., Shapiro, L., Moerner, W. E., Wakatsuki, S. Dissection of Protein Function Within a Bacterial Biomolecular Condensate by In Vitro Reconstitution. x@caltech.edu, x=wcoleman, George Daghlian 2016 University of Illinois at Chicago, Graduate Student, Biochemistry A specific binding activity for the region between -81 and -122 base-pairs was shown to be temporally controlled, appearing prior to the activation of hook operon transcription. This conclusion is based on the observations that (i) methionine auxotrophs starved of methionine can swim only in the forward direction (comparable to smooth swimming in the enteric bacteria), (ii) a specific set of membrane proteins was found to be methylated in vivo and the incorporated [3H]methyl groups were alkali sensitive, (iii) this same set of membrane proteins incorporated methyl groups from S-adenosylmethionine in vitro, and (iv) out of a total of eight generally nonchemotactic mutants, two were found to swim only in a forward direction and one of these lacked methyltransferase activity. View details for Web of Science ID A1990CW01800056. We have begun studies with RNA polymerase purified from Caulobacter crescentus to determine whether cell factors or alterations in the enzyme structure serve to change the specificity of transcription during the cell cycle. The IHF protein and the ftr-binding protein is primarily restricted to the predivisional cell, the cell type in which these promoters are transcribed. The bacterium Caulobacter crescentus uses a ParA-based partitioning system to segregate newly replicated chromosomal centromeres to opposite cell poles. When parS is moved farther from the origin, the cell waits for parS to be replicated before segregation can begin. Rock, F. L., Mao, W., Yaremchuk, A., Tukalo, M., Crepin, T., Zhou, H., Zhang, Y., Hernandez, V., Akama, T., Baker, S. J., Plattner, J. J., Shapiro, L., Martinis, S. A., Benkovic, S. J., Cusack, S., Alley, M. R. High-throughput identification of transcription start sites, conserved promoter motifs and predicted regulons. Bacteria deploy proteins and protein complexes to particular locations and do so in a dynamic manner in lockstep with the organized deployment of their chromosome. We postulate that IHF mediates the formation of a higher order structure between the divergent promoter regions in a manner analogous to the nucleosome-like structure generated for lambda-Escherichia coli DNA recombination and that this higher order structure modulates transcription. IS1 and IS5 appear limited to the enteric bacteria, whereas IS2 sequences can also be detected in Pseudomonas putida, Pseudomonas aeruginosa, and Serratia marcescens. Our results elucidate a bacterial chromosome segregation mechanism that features basic operating principles similar to eukaryotic mitotic machines, including a multivalent protein complex at the centromere that stimulates the dynamic disassembly of polymers to move chromosomes into daughter compartments. B.Sc. Importantly, RNase E cluster positions correlated with the subcellular location of chromosomal loci of two highly transcribed rRNA genes, suggesting that RNase E's function in rRNA processing occurs at the site of rRNA synthesis. View details for DOI 10.1073/pnas.1906119116, View details for DOI 10.1016/j.bpj.2018.11.881, View details for Web of Science ID 000460779800789, View details for DOI 10.1016/j.bpj.2018.11.2446, View details for Web of Science ID 000460779802279, View details for DOI 10.1016/j.bpj.2018.11.056, View details for Web of Science ID 000460779800028, View details for DOI 10.1016/j.bpj.2018.11.1077, View details for Web of Science ID 000460779800965, View details for DOI 10.1016/j.bpj.2018.11.2475, View details for Web of Science ID 000460779802305. We propose that this ParB-stimulated ParA depolymerization activity moves the centromere to the opposite cell pole through a burnt bridge Brownian ratchet mechanism. Currently: Associate Director of ML/AI We show here that genes differentially expressed in a ctrA temperature-sensitive (ts) mutant are similarly affected in a cckA ts mutant, that the phosphorylation of CckA coincides temporally with CtrA phosphorylation during the cell cycle, and that CckA is essential for viability because it is required for CtrA phosphorylation. The S ring has a triangular cross section, the sides of the triangle abutting the E ring, the rod and the M ring. Sequence analysis of a complementing subclone revealed that this locus encodes at least two proteins that are homologs of the Salmonella typhimurium and Escherichia coli flagellar proteins FliL and FliM. The acidic phospholipids, phosphatidylglycerol and cardiolipin, comprise approximately 87% of the total phospholipids. This RNA encodes a peptide tag that is incorporated at the end of the aberrant polypeptide and targets it for proteolysis. Regulatory factors that initiate forespore-specific transcription during Bacillus subtilis sporulation respond to adenosine nucleotide ratios. An additional parallel between the ccrM and class II flagellar promoters is that their transcription responds to a cell cycle DNA replication checkpoint. The bacterial flagellum is a complex structure composed of a transmembrane basal body, a hook, and a filament. Transcription of a flbN-reporter gene fusion in an Escherichia coli background was dependent on the presence of a NifA transcription factor supplied by a plasmid-borne Rhizobium meliloti gene encoding NifA. Our correlative approach reveals that SpmX localizes along one side of the cell pole and its extent closely matches that of the PopZ region. Common sites for localized components are the poles of rod-shaped cells, which are dynamically modified in composition and function in order to control cellular physiology. By expressing an inducible roGFP2-PopZ fusion we can visualize individual microdomains in the context of their redox environment. WebShe is a co-editor of Philanthropy in Democratic Societies (2016, Chicago University Press) and of the forthcoming volume Digital Technology and Democratic Theory. View details for Web of Science ID A1996VW70900002. View details for PubMedCentralID PMC3859194. Beyond direct protein coding, genomes encode regulatory information required to orchestrate the proper timing and levels of gene expression and protein synthesis, and contain binding sites and regulatory sequences to co-ordinate the activities of proteins involved in chromosome repair and maintenance. To the best of our knowledge, this is the first demonstration of the use of fluorogen activating proteins for super-resolution imaging in live bacterial cells. We have a lot of different ways to manipulate particle beams inside of accelerators, but we dont have a really precise way to describe a beams shape and momentum, SLAC accelerator scientist and lead author Ryan Roussel said. WebBio. The tests described have been developed and their performance characteristics determined by the CLIA-certified laboratory performing the test. shapiro lab stanfordorleans parish documentary transaction tax. WEISSBORN, A., Steinman, H. M., Shapiro, L. SYNTHESIS OF SPECIFIC MEMBRANE-PROTEINS IS A FUNCTION OF DNA-REPLICATION AND PHOSPHOLIPID-SYNTHESIS IN CAULOBACTER-CRESCENTUS. The released flagellum is composed of a filament, hook, and rod. Single-molecule imaging enables biophysical measurements devoid of ensemble averaging, gives enhanced spatial resolution beyond the optical diffraction limit, and enables superresolution reconstruction of structures beyond the diffraction limit. We propose that SMC spuriously links the duplicated chromosome immediately after passage of the replication fork. We illustrate the workflow by annotating the positions of three proteins in the bacterium Caulobacter crescentus: McpA, PopZ, and SpmX. x@gmail.com, x=wheesoo1031, Young-Joo Kim, PhD Expression of the latter two phenotypes required complex media and both were repressed by glucose. WebAs the first student, Soso declared open the lab at the 2016 Shriram new lab welcome party. Approximately 1,500 to 2,000 SMC molecules are present per cell during active growth, corresponding to one SMC complex per 6,000 to 8,000 bp of chromosomal DNA. The bacterium Caulobacter crescentus divides asymmetrically to yield two functionally distinct cells: a motile, chemotactic swarmer cell, and a sessile stalked cell with replication and division capabilities. Goley, E. D., Dye, N. A., Werner, J. N., Gitai, Z., Shapiro, L. CrfA, a small noncoding RNA regulator of adaptation to carbon starvation in Caulobacter crescentus. The first generation of acoustic reporter genes proved a concept but were insensitive, burdensome and impossible to image continuously. The trapping of enzyme-bound tRNA(Leu) in the editing site prevents catalytic turnover, thus inhibiting synthesis of leucyl-tRNA(Leu) and consequentially blocking protein synthesis. Even in Escherichia coli, which is generally thought to be symmetrical, old poles are more static than new poles with respect to cell wall assembly (1), and they differ in the deposition of phospholipid domains (2). View details for DOI 10.1146/annurev.micro.56.012302.161103, View details for Web of Science ID 000179054200025. x@caltech.edu, x=blling, Ann Liu The timing of transcription of two master regulator genes and two cell division genes is controlled by the methylation state of GANTC sites in their promoters. We participated in the largest prospective studies to date in molecular diagnostics in oncology (CIRCULATE), womens health (SMART), and organ health (Trifecta). At higher concentrations, calcium ions stabilize monomeric RsaA, which can then transition to the two-dimensional crystalline state. Delft University of Technology, Dr. Pradeep Ramesh Analysis of in vivo and in vitro methylation in synchronized cultures showed that the methylation reaction is lost when the flagellated swarmer cell differentiates into a stalked cell. Ptacin, J. L., Lee, S. F., Garner, E. C., Toro, E., Eckart, M., Comolli, L. R., Moerner, W., Shapiro, L. Polar Remodeling and Histidine Kinase Activation, Which Is Essential for Caulobacter Cell Cycle Progression, Are Dependent on DNA Replication Initiation. DnaA boxes are present upstream of many genes whose expression requires DnaA, and His6-DnaA binds to the promoters of gcrA, ftsZ and podJ in vitro. View details for DOI 10.1038/sj.emboj.7600935, View details for Web of Science ID 000234952500011, View details for PubMedCentralID PMC1383518. B.A.Sc. Moreover, initiation of DNA replication is allowed only once per cell cycle. An analysis of the time of activation of every cell-cycle regulatory transcription start site, coupled to both the position of a GANTC site in their promoter regions and the time in the cell cycle when the GANTC site transitions from full to hemimethylation, allowed the identification of 59 genes as candidates for epigenetic regulation. Caulobacter crescentus wild-type strain CB13 is unable to utilize galactose as the sole carbon source unless derivatives of cyclic AMP are present. The Department is a dynamic, interactive research community situated in one of the world's best environments for biomedical research. Therefore phospholipid synthesis is required for stalk elongation in C. crescentus. View details for DOI 10.1016/j.tcb.2007.03.005, View details for Web of Science ID 000246939100005. Cut through the jargon while exploring our research. Positional cues are equally important in coordinating movement of the chromosome with cell division site selection in Caulobacter. Stanford AI Lab Papers and Talks at ICLR 2023. We also reexamined chromosome partitioning in a recombination-deficient strain of C. crescentus, and confirmed an earlier report that chromosomes partition to the progeny stalked and swarmer cells in a random manner that does not discriminate between old and new DNA strands. One-third of these target genes encode putative TonB-dependent receptors, suggesting CrfA plays a role in the surface modification of C. crescentus, facilitating the uptake of nutrients during periods of carbon starvation. Both had a profound effect on the kinds of questions I posed and the means I used to arrive at answers. During development of the symbiotic soil bacterium Sinorhizobium meliloti into nitrogen-fixing bacteroids, DNA replication and cell division cease and the cells undergo profound metabolic and morphological changes. We view Developmental Biology in the broadest sense, encompassing Microbes to Humans and employing a wide variety of molecular and genetic approaches as well as systems level biology, engineering, and computational science. Rate enhancement of protein crystallization by a discrete nucleation domain may enable engineering of kinetically controllable self-assembling 2D macromolecular nanomaterials. Wagenknecht, T., DeRosier, D., Shapiro, L., WEISSBORN, A. PHOSPHOLIPID BIOSYNTHESIS IS REQUIRED FOR STALK ELONGATION IN CAULOBACTER-CRESCENTUS. Homologs of GapR, which are ubiquitous among the -proteobacteria and are encoded on multiple bacteriophage genomes, also accumulate in the predivisional cell swarmer compartment when expressed in Caulobacter The Escherichia coli nucleoid-associated protein H-NS, like GapR, selectively associates with AT-rich DNA, yet it does not localize preferentially to the swarmer compartment when expressed exogenously in Caulobacter, suggesting that recognition of AT-rich DNA is not sufficient for the asymmetric accumulation of GapR. Research Technician, 2019-2021 UCSD, Prof. George Lu View details for Web of Science ID A1986E228900007. These results indicate that the rapidly reassociating fraction derives from inverted repeat sequences within the chromosome and not from cross-links or plasmids. CtrA is more stable in the presence of CckA than it is absence, suggesting that CckA may also be involved, directly or indirectly, in the regulation of CtrA proteolysis. The diameters of the two upper rings differed, being 32 and 21 nm, respectively. Fluorescence microscopy can potentially be used to reveal this information when specific labels, known as fluorescent biosensors, are used, but there has been minimal use of such biosensors in cryo-CLEM to date. Critically, many of these functions occur at defined locations within the cell, and therefore regulators of each module must communicate to remain coordinated in space. Enzyme from pure populations of stalked cells, as well as populations enriched in swarmer and predivisional cells, appeared identical in subunit structure and template requirements. Both proteins contain multiple PAS domains, a multifunctional class of sensory domains present across the kingdoms of life. B.A., Physics, University of Chicago, 1984. Emilio received his B.S. The global regulatory architecture of transcription during the Caulobacter cell cycle. The C. crescentus homologues of several Escherichia coli genes are adjacent to the origin in the physical order hemE, origin, dnaA and dnaK,J. The content on this website is intended to be used for informational purposes only. Milton and Francis Clauser Doctoral Prize Winner (top PhD thesis at Caltech) View details for DOI 10.1038/s41467-019-10650-x. The second PAS domain interacts with the asymmetrically partitioned second messenger cyclic-di-GMP, inhibiting kinase activity while stimulating phosphatase activity, consistent with the selective inactivation of CtrA in the incipient stalked cell compartment. Perez, A. M., Mann, T. H., Lasker, K., Ahrens, D. G., Eckart, M. R., Shapiro, L. Super-Resolution Microscopy and Single-Protein Tracking in Live Bacteria Using a Genetically Encoded, Photostable Fluoromodule. Phospho-signaling proteins and proteases dynamically deployed to specific locations on the cell wall are vital. Understanding the order of divisome assembly would inform models of the interactions among its components and their respective functions. Particularly, hybrid tags that combine a fluorescent or fluorogenic dye with a genetically encoded protein (such as enzymatic labels) have been used successfully in multiple cell types. Our observations suggest that the processivity of C. crescentus replication requires concomitant phospholipid synthesis and that cell death results from incomplete replication of the chromosome. Ph.D. Mech. Physics, expected 2023 Caltech An asynchronous sequential digital circuit model equivalent to the validated simulation model was created. MmpA appears to cleave within or near the transmembrane segment of PodJS, releasing it into the cytoplasm for complete proteolysis. Overexpression of CcrM in either bacterium results in defects in cell division and cell morphology and in the initiation of DNA replication. Disruption of the hrcA gene, homologs of which are also found upstream of grpE in other bacteria, increased transcription of the groESL operon, and this effect was dependent on the presence of an intact CIRCE element. Delighted to host the first International Symposium on Biomolecular Ultrasound and Sonogenetics. This DNA contains sequence motifs that are common to other bacterial origins, such as five DnaA boxes, an E. coli-like 13-mer, and an exceptional A + T-rich region. DeepMind, Dr. Arash Farhadi Copyright 2023 Mikhail G. Shapiro | Powered by. The researchersdetailed their algorithm and method in April in Physical Review Letters. These changes in DNA methylation could signal differential binding of regulatory proteins to activate or repress transcription. View details for DOI 10.1073/pnas.0402153101. However, flaO expression appears to be under negative control by two regulatory genes flaS and flaW. Ph.D. Student, Biology The production of these different transcripts by the E. coli enzyme was dependent on salt concentration and, in at least one case, appeared to be the result of differential termination. Observing crystallization using a time course of electron cryo-microscopy (Cryo-EM) imaging reveals a crystalline intermediate wherein N-terminal nucleation domains exhibit motional dynamics with respect to rigid lattice-forming crystallization domains. Such organization is transmitted from one generation to the next by progressive segregation of daughter chromosomes and anchoring of DNA to the cell envelope. View details for DOI 10.1016/j.cell.2005.12.033. RNA PRODUCT OF A REACTION CATALYZED BY A VIRAL RNA-DEPENDENT RNA POLYMERASE, Freeman Spogli Institute for International Studies, Institute for Computational and Mathematical Engineering (ICME), Institute for Human-Centered Artificial Intelligence (HAI), Institute for Stem Cell Biology and Regenerative Medicine, Stanford Institute for Economic Policy Research (SIEPR), Stanford Woods Institute for the Environment, Office of VP for University Human Resources, Office of Vice President for Business Affairs and Chief Financial Officer, Directed Reading in Developmental Biology, DOI 10.1146/annurev.genet.41.110306.130346, DOI 10.1146/annurev.biochem.72.121801.161824, DOI 10.1146/annurev.micro.56.012302.161103. Chromatographic mobilities suggested that these fatty acids may be a cyclopropane and a branched-chain fatty acid. Mechanical and Aerospace Engineering, Seoul National University View details for Web of Science ID A1996UD48400009, View details for PubMedCentralID PMC177876. View details for DOI 10.1128/AEM.01566-07, View details for Web of Science ID 000251474400017, View details for PubMedCentralID PMC2168040. In Caulobacter crescentus the biosynthesis and assembly of this structure is under temporal and spatial control. Comerci, C. J., Herrmann, J., Yoon, J., Jabbarpour, F., Zhou, X., Nomellini, J. F., Smit, J., Shapiro, L., Wakatsuki, S., Moerner, W. E. Robust Modulation of a Bacterial Kinase by Protein Phase Separation. The characteristics that differentiate one daughter cell from the other result from differential transcription and subcellular positioning of regulatory and structural proteins. Biological Engineering, MIT x@caltech.edu, x=rnayak, Nivin N. Nystrm, PhD In addition, we demonstrated that the fatty acid composition of wild-type C. crescentus can be altered by growing the cells in medium supplemented with any one of a variety of unsaturated fatty acids. View details for DOI 10.1073/pnas.062065699, View details for Web of Science ID 000174856000089, View details for PubMedCentralID PMC123699. View details for Web of Science ID A1976CU45400006, View details for Web of Science ID A1976CK72400002. Ph.D. Student, Bioengineering The pleiotropic regulation of flagellin synthesis, assembly, and chemotaxis methylation functions exhibited by both the flaY and flaE genes suggest that their gene products function in a regulatory hierarchy that controls both flagellar and chemotaxis gene expression. Coactivator Studies, Progesterone Receptor, University of North Carolina, Chapel Hill & Aero. Although several sequence and structural motifs that are conserved among one-piece tmRNAs have been lost, the alpha-proteobacterium Caulobacter crescentus produces a functional two-piece tmRNA. The properties of the DNA from bacteriophage phiCbK are similar to those of host C. crescentus DNA with respect to buoyant density, thermal transition point, and guanine plus cytosine content. View details for DOI 10.1073/pnas.0807448105, View details for Web of Science ID 000260360500041, View details for PubMedCentralID PMC2563096. Chemical and Biomolecular Engineering, Johns Hopkins University View details for DOI 10.1073/pnas.1612579113, View details for Web of Science ID 000384528900022, View details for PubMedCentralID PMC5056096. B., Shen, X., Shapiro, L., McAdams, H. H. Initiating bacterial mitosis Understanding the mechanism of ParA-mediated chromosome segregation, The Caulobacter Tol-Pal Complex Is Essential for Outer Membrane Integrity and the Positioning of a Polar Localization Factor. Analysis of the cloned C. crescentus dnaA gene has shown that the deduced amino acid sequence can encode a 486-amino-acid protein that is 37% identical to the DnaA protein of Escherichia coli. Thus, a step in the pathway that establishes the characteristic asymmetry of the C. crescentus cell appears to be disrupted in flbT mutants. Postdoc. Vivek Bharadwaj, Ph11 Scholar 2017 PhD at UC Berkeley, Making engineered cells dance to ultrasound, Researchers Make it Possible for Ultrasound to Reveal Gene Expression in the Body, Vilcek Foundation Prize Awarded to Mikhail Shapiro, CCE Postdoc Receives NIH Pathway to Independence Award, Mikhail Shapiro Wins Roger Tsien Award for Excellence in Chemical Biology, Program Brings Area High School Students, Teachers into Caltech Labs, Switching Brain Circuits On and Off Without Surgery, Mikhail Shapiro Selected as Camille Dreyfus Teacher-Scholar, Taking MRI Technology down to Micrometer Scales, Scientists Design Bacteria to Reflect Sonar Signals for Ultrasound Imaging, Biologists Give Bacteria Thermostat Controls, Designing Ultrasound Tools with Lego-Like Proteins, Newly Named Pew Scholar to Image Gut Bacteria with Sound Waves, Partnership with Heritage Medical Research Institute Will Augment Translational Medicine Research, Abedi Receives Fellowship for New Americans, Caltech Researchers Receive NIH BRAIN Funding, New Method Could Improve Ultrasound Imaging, x@caltech.edu; x=mikhail