Matching Items (99)
Description
Diacylglycerol kinase catalyses the ATP-dependent conversion of diacylglycerol to phosphatidic acid in the plasma membrane of Escherichia coli. The small size of this integral membrane trimer, which has 121 residues per subunit, means that available protein must be used economically to craft three catalytic and substrate-binding sites centred about the membrane/cytosol interface. How nature has accomplished this extraordinary feat is revealed here in a crystal structure of the kinase captured as a ternary complex with bound lipid substrate and an ATP analogue. Residues, identified as essential for activity by mutagenesis, decorate the active site and are rationalized by the ternary structure. The γ-phosphate of the ATP analogue is positioned for direct transfer to the primary hydroxyl of the lipid whose acyl chain is in the membrane. A catalytic mechanism for this unique enzyme is proposed. The active site architecture shows clear evidence of having arisen by convergent evolution.
ContributorsLi, Dianfan (Author) / Stansfeld, Phillip J. (Author) / Sansom, Mark S. P. (Author) / Keogh, Aaron (Author) / Vogeley, Lutz (Author) / Howe, Nicole (Author) / Lyons, Joseph A. (Author) / Aragao, David (Author) / Fromme, Petra (Author) / Fromme, Raimund (Author) / Basu, Shibom (Author) / Grotjohann, Ingo (Author) / Kupitz, Christopher (Author) / Rendek, Kimberley (Author) / Weierstall, Uwe (Author) / Zatsepin, Nadia (Author) / Cherezov, Vadim (Author) / Liu, Wei (Author) / Bandaru, Sateesh (Author) / English, Niall J. (Author) / Gati, Cornelius (Author) / Barty, Anton (Author) / Yefanov, Oleksandr (Author) / Chapman, Henry N. (Author) / Diederichs, Kay (Author) / Messerschmidt, Marc (Author) / Boutet, Sebastien (Author) / Williams, Garth J. (Author) / Seibert, M. Marvin (Author) / Caffrey, Martin (Author) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2015-12-17
Description
Phytochromes are a family of photoreceptors that control light responses of plants, fungi and bacteria. A sequence of structural changes, which is not yet fully understood, leads to activation of an output domain. Time-resolved serial femtosecond crystallography (SFX) can potentially shine light on these conformational changes. Here we report the room temperature crystal structure of the chromophore-binding domains of the Deinococcus radiodurans phytochrome at 2.1 Å resolution. The structure was obtained by serial femtosecond X-ray crystallography from microcrystals at an X-ray free electron laser. We find overall good agreement compared to a crystal structure at 1.35 Å resolution derived from conventional crystallography at cryogenic temperatures, which we also report here. The thioether linkage between chromophore and protein is subject to positional ambiguity at the synchrotron, but is fully resolved with SFX. The study paves the way for time-resolved structural investigations of the phytochrome photocycle with time-resolved SFX.
ContributorsEdlund, Petra (Author) / Takala, Heikki (Author) / Claesson, Elin (Author) / Henry, Leocadie (Author) / Dods, Robert (Author) / Lehtivuori, Heli (Author) / Panman, Matthijs (Author) / Pande, Kanupriya (Author) / White, Thomas (Author) / Nakane, Takanori (Author) / Berntsson, Oskar (Author) / Gustavsson, Emil (Author) / Bath, Petra (Author) / Modi, Vaibhav (Author) / Roy Chowdhury, Shatabdi (Author) / Zook, James (Author) / Berntsen, Peter (Author) / Pandey, Suraj (Author) / Poudyal, Ishwor (Author) / Tenboer, Jason (Author) / Kupitz, Christopher (Author) / Barty, Anton (Author) / Fromme, Petra (Author) / Koralek, Jake D. (Author) / Tanaka, Tomoyuki (Author) / Spence, John (Author) / Liang, Mengning (Author) / Hunter, Mark S. (Author) / Boutet, Sebastien (Author) / Nango, Eriko (Author) / Moffat, Keith (Author) / Groenhof, Gerrit (Author) / Ihalainen, Janne (Author) / Stojkovic, Emina A. (Author) / Schmidt, Marius (Author) / Westenhoff, Sebastian (Author) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2016-10-19
Description
Antibodies are essential for structural determinations and functional studies of membrane proteins, but antibody generation is limited by the availability of properly-folded and purified antigen. We describe the first application of genetic immunization to a structurally diverse set of membrane proteins to show that immunization of mice with DNA alone produced antibodies against 71% (n = 17) of the bacterial and viral targets. Antibody production correlated with prior reports of target immunogenicity in host organisms, underscoring the efficiency of this DNA-gold micronanoplex approach. To generate each antigen for antibody characterization, we also developed a simple in vitro membrane protein expression and capture method. Antibody specificity was demonstrated upon identifying, for the first time, membrane-directed heterologous expression of the native sequences of the FopA and FTT1525 virulence determinants from the select agent Francisella tularensis SCHU S4. These approaches will accelerate future structural and functional investigations of therapeutically-relevant membrane proteins.
ContributorsHansen, Debra (Author) / Robida, Mark (Author) / Craciunescu, Felicia (Author) / Loskutov, Andrey (Author) / Dorner, Katerina (Author) / Rodenberry, John-Charles (Author) / Wang, Xiao (Author) / Olson, Tien (Author) / Patel, Hetal (Author) / Fromme, Petra (Author) / Sykes, Kathryn (Author) / Biodesign Institute (Contributor) / Innovations in Medicine (Contributor) / Applied Structural Discovery (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor)
Created2016-02-24
Description
Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.
ContributorsNogly, Przemyslaw (Author) / Panneels, Valerie (Author) / Nelson, Garrett (Author) / Gati, Cornelius (Author) / Kimura, Tetsunari (Author) / Milne, Christopher (Author) / Milathianaki, Despina (Author) / Kubo, Minoru (Author) / Wu, Wenting (Author) / Conrad, Chelsie (Author) / Coe, Jesse (Author) / Bean, Richard (Author) / Zhao, Yun (Author) / Bath, Petra (Author) / Dods, Robert (Author) / Harimoorthy, Rajiv (Author) / Beyerlein, Kenneth R. (Author) / Rheinberger, Jan (Author) / James, Daniel (Author) / Deponte, Daniel (Author) / Li, Chufeng (Author) / Sala, Leonardo (Author) / Williams, Garth J. (Author) / Hunter, Mark S. (Author) / Koglin, Jason E. (Author) / Berntsen, Peter (Author) / Nango, Eriko (Author) / Iwata, So (Author) / Chapman, Henry N. (Author) / Fromme, Petra (Author) / Frank, Matthias (Author) / Abela, Rafael (Author) / Boutet, Sebastien (Author) / Barty, Anton (Author) / White, Thomas A. (Author) / Weierstall, Uwe (Author) / Spence, John (Author) / Neutze, Richard (Author) / Schertler, Gebhard (Author) / Standfuss, Jorg (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / School of Molecular Sciences (Contributor)
Created2016-08-22
Description
The Walter Cronkite School of Journalism and Mass Communications stands as a "gold standard" of journalism education throughout the country. In my time at the school though, I found that some aspects in the whole of the curriculum were missing. I as well as several other friends became interested in production and the technical side of things. This seemed to be the direction we wanted to go and soon realized this played a crucial part in journalism. Although there is a studio production class and a studio production track through the immersive Cronkite News program, there is not much in between. This inspired me to take a look deeper into production skills and their place within a journalism education. The project is split into three main sections that dive into the ideas of teaching production skills and technical skills to journalism students and whether or not it is valuable. The first part is the background of the project and why this project came to be. The background section explores the inspiration for the project. The project continues with a look at job statistics and where the industry currently sits. This continues into the final section that contains personal stories and interviews with professionals in the field. This is a critical section to back up claims made through research and evaluation. There is a lot of personal experience and non-traditional research done through this project, but the assertions and conclusions made are clear. Through job statistics, personal stories, and interviews with professionals, this project examines how production could be taught in a traditional journalism program. These stories show that a journalism curriculum may not be the best place to teach production in depth, but that it still is an incredibly important part of the journalism world as a whole.
ContributorsHardy, Joseph Michael (Author) / Jacoby, Jim (Thesis director) / McJannet, Rob (Committee member) / College of Public Service and Community Solutions (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The Chinese tourism market has become the largest tourism market in the world and continues to show promise in its future development. Global destinations such as Southeast Asia, France and now Australia have begun to see a major boom in Chinese tourists within the past decade due to less restrictive travel policies, a growing economy and higher disposable income rates within urban centers in China. Australia has become the top destination among Chinese citizens that wish to travel due to its coastal and beach attractions, unique wildlife, and general welcoming attitude toward Chinese citizens. As the market continues to grow, the characteristics and demographics change as well. The Chinese government did not allow for international travel until the early 1990s. During this time, package tours offered by government-regulated travel agencies were the prominent method of travel planning with travelers over the age of 35 making up the majority of travelers. However, in the past decade there has been a shift from group travel toward independent travel due to higher income and more independence among young adults. There remains a stigma against Chinese tourists due to behavioral and cultural challenges Chinese tourists face when traveling abroad, but as Chinese travelers begin to travel in smaller groups and have greater exposure to international cultures, these negative stereotypes will start to disappear. This paper focuses on the impact the Chinese tourism market has on Cairns, Australia. Cairns is characterized by its backpacking culture, easy access to environmental attractions and a high number of annual travelers from Asia and China specifically. The paper uses qualitative research and compiles information from news sources, government documents and statistical data regarding Chinese outbound tourism and its impacts on Australian tourism. There is also a case study composed of personal observations of a nature park in North Queensland which uses specific marketing and attraction coordination to appeal to Chinese tourists. This case study analyzes the tactics used by local destinations that cater to group travel over independent travel and points out the benefits of this type of specialized tourism. The research concludes by arguing the trend toward independent travel is beneficial to the Cairns tourism industry rather than harmful as long as the industry recognizes the new trends in Chinese tourism and does not focus on the previous trends of group travel when appealing to Chinese tourists. Instead, the industry should continue to focus on the backpacking culture and work toward catering to the demands of millennial travelers.
ContributorsRochon, Jacob Henri (Author) / Goodman, Rebekka (Thesis director) / McWilliams, Claire (Committee member) / College of Public Service and Community Solutions (Contributor) / School of Politics and Global Studies (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
This project uses the format of a web-based choose-your-own-adventure game to integrate allusions, themes, and symbolism presented throughout Hellenic and Medieval literature. The research draws upon translations of The Aeneid by Virgil, Perceval by Chrétien de Troyes, Physica by Hildegard of Bingen, The Canterbury Tales by Geoffrey Chaucer, Sir Gawain and the Green Knight as well as various Celtic, Germanic, and Greco-Roman myths and figures. The game itself draws on writing theory as exemplified in The Writer's Journey by Christopher Vogler, which sets the archetype of what constitutes a Hero and the stages a character must undergo to become that Hero. Hosted on an online game creation program called Inklewriter, the game presents a scenario, starting with a knight, waking up in a tree with no previous recollection of getting there, and the reader is given clickable options to choose in response to the situation.
The ultimate purpose of this project is to serve as an educational resource, wherein links to the alluded material and analyses of symbolism can help students find source material based on their interests, serve as a guide for critical analysis of literature, and exemplify how writing theory can be implemented into a narrative. Though this project is presently incomplete, the link to the game contains the introductory scenes and the following analysis exemplifies the writing process, explains the choice and integration of alluded material and symbolism, and describes several scenes that are to be completed in the future.
The ultimate purpose of this project is to serve as an educational resource, wherein links to the alluded material and analyses of symbolism can help students find source material based on their interests, serve as a guide for critical analysis of literature, and exemplify how writing theory can be implemented into a narrative. Though this project is presently incomplete, the link to the game contains the introductory scenes and the following analysis exemplifies the writing process, explains the choice and integration of alluded material and symbolism, and describes several scenes that are to be completed in the future.
ContributorsCarr, Gillian Elizabeth (Author) / Sturges, Robert (Thesis director) / Corse, Taylor (Committee member) / Department of English (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The following is a fantasy twist on the Christian Bible, set before the time of Adam of Eve. The plot follows the lives of the first humans before Adam and Eve, the Father's first attempt at creating humanity. Additionally, it follows the first generation of archangels on an adventure into the abyss. The work draws on theological, and mythological ideas including Greek mythology, Hasidic legend, John Milton's Paradise Lost, and even Dungeons and Dragons.
ContributorsWhite, Zachary Christopher (Author) / Sturges, Robert (Thesis director) / Corse, Taylor (Committee member) / Barrett, The Honors College (Contributor) / Department of English (Contributor)
Created2014-05
Description
Though people are beginning to analyze the internet as an active social force, a seemingly insurmountable problem permeates all criticisms of the world wide web: how do we begin to frame the Internet as a subject of inquiry when its role in our lives is constantly shifting, continually slipping from definition, yet undeniably reconstructing a new human condition? I believe an answer may lie in placing the Internet within the context of the Faust Myth \u2014 a legend that has repeatedly been used to explore humanity's obsession with power. For my undergraduate honors thesis, I wrote and performed an adaptation of Christopher Marlowe's Doctor Faustus in which I frame the Internet as a modern Faustian contract, and advocate a new approach to the use of technology.
ContributorsMunger, Adrielle Karen (Author) / Sturges, Robert (Thesis director) / Sterling, Pamela (Committee member) / Finn, Ed (Committee member) / Barrett, The Honors College (Contributor) / Department of English (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2013-05
Description
Previous research has found improvements in motor and cognitive measures following Assisted Cycle Therapy (AC) in adolescence with Down syndrome (DS). Our study investigated whether we would find improvements in older adults with DS on measures of leisure physical activity (GLTEQ) and sleep, which are early indicators of Alzheimer's disease (AD) in persons with Down syndrome. This study consisted of eight participants with Down syndrome between 31 and 51 years old that cycled for 30 minutes 3 x/week for eight weeks either at their voluntary cycling rate (VC) or approximately 35% faster with the help of a mechanical motor (AC). We predicted that, based on pilot data (Gomez, 2015), GLTEQ would either maintain or improve after AC, but would decrease after VC and would stay the same after NC. We predicted that the sleep score may improve after both VC or AC or it may improve more after VC than AC based on pilot data related to leisure activity. Our results were consistent with our prediction that GLTEQ will either maintain or improve after AC but will decrease after VC. Our results were not consistent with our prediction that sleep may improve after both VC or AC or it may improve more after VC than AC, possibly because we did not pre-screen for sleep disorders. Future research should focus on recruiting more participants and using both objective and subjective measures of sleep and physical activity to improve the efficacy of the study.
ContributorsParker, Lucas Maury (Author) / Ringenbach, Shannon (Thesis director) / Buman, Matthew (Committee member) / Holzapfel, Simon (Committee member) / School of Social and Behavioral Sciences (Contributor) / School of Nutrition and Health Promotion (Contributor) / College of Public Service and Community Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05