Matching Items (204)
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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

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
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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

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
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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

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
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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.

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 past two and a half semesters have been extremely difficult for college students. Due to the COVID-19 pandemic, student motivation has been slipping. I felt my own productivity slowly diminishing shortly after March 2020, and a number of students that I have spoken with share a similar mentality. In

The past two and a half semesters have been extremely difficult for college students. Due to the COVID-19 pandemic, student motivation has been slipping. I felt my own productivity slowly diminishing shortly after March 2020, and a number of students that I have spoken with share a similar mentality. In addition, the social lives of students have taken a toll. Social distancing, event cancellations and online classes have led to a serious lack of social interaction with their peers. I felt as though the theatre community, in particular, was suffering, because of how much of our lives are centered around social interaction. Not only is social interaction recreational for us theatre students, but it’s integral for our careers as well. We are very conditioned to getting together multiple times a week just to experience emotion with each other, and this was all taken away very abruptly in March 2020. The remaining theatrical events last season were cancelled, and the events this season were mostly moved to an online setting. I began to think that the theatre community at ASU needed some way to stay connected despite these unfortunate circumstances, and that is when I found out about Alpha Psi Omega. Alpha Psi Omega is a National Theatre Honors Society which used to have a chapter here at ASU, so I took it upon myself to reactivate the chapter.

ContributorsGerardi, Michael (Author) / McAvoy, Mary (Thesis director) / Duren, Randy (Committee member) / Hugh Downs School of Human Communication (Contributor) / School of Music, Dance and Theatre (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

Research has shown that being a female athlete in a male-dominated sports world is an oppressive burden, yet the experiences of being a black female athlete have been largely ignored. To combat this lack of attention, this paper invokes communication and feminist theorist Bell Hook's concept of moving black women

Research has shown that being a female athlete in a male-dominated sports world is an oppressive burden, yet the experiences of being a black female athlete have been largely ignored. To combat this lack of attention, this paper invokes communication and feminist theorist Bell Hook's concept of moving black women from margin to center to reveal the intersectional oppression of gender and racial narratives that they face in sports. By outlining the difference between white and black femininity and studying media portrayals of popular black female athletes such as Venus and Serena Williams and others, it becomes obvious how black women are typecast into certain social and athletic roles. This research also includes an auto-ethnographic component of my own experience as a black female lacrosse player at the NCAA Division I level. This component functions as a point of comparison and contrast of the ideas and concepts I discuss. Lastly, I offer recommendations and suggestions as to how to empower young black female athletes and retain them in a variety of sports. The goal of my thesis is to place special attention onto black women in an area which there is an extreme lack of representation. My own empirical research has led me to the conclusion that not only is such a discussion important, but it is absolutely necessary. If we are to fight back against hegemonic social structures such as racism and gender roles in the sports world, we must first understand what we are up against. My thesis gives us a glimpse into our imposing opponents, and I hope that future research continues this trend so that black female athletes like myself may one day be considered an athlete in the same sense that our white peers are.

ContributorsWright, Daniela Casselle (Author) / Edson, Belle (Thesis director) / Zanin, Alaina (Committee member) / Hugh Downs School of Human Communication (Contributor) / School of Social Transformation (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

This work explores the dynamic of gender and sport through the lens of Title IX, with the intention of highlighting the importance of gender equality within athletics.

ContributorsVigil, Amanda Beth (Author) / Kassing, Jeffrey (Thesis director) / Shearer, Emilee (Committee member) / Hugh Downs School of Human Communication (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Website usage on both smartphone and tablet devices is rapidly increasing. Website success hinges largely upon how well information on the site is recalled and perceived. The purpose of this study is to explore the question of whether or not the differences in display size and resolution of smartphone versus

Website usage on both smartphone and tablet devices is rapidly increasing. Website success hinges largely upon how well information on the site is recalled and perceived. The purpose of this study is to explore the question of whether or not the differences in display size and resolution of smartphone versus tablet devices affect the recall of website information. I hypothesize that tablets will produce greater website recall than smartphones, due to their larger screen size and higher resolution which may reduce cognitive strain. During the study, participants viewed a sample website for two minutes on either an iPhone or iPad, and then participated in a brief 20 question memory test to evaluate how well they remembered the website information. Although test scores for the iPad users were about one test point higher than test scores for the iPhone users, the difference was not statistically significant. However, the study was limited by the low sample size (n = 94). This indicates that further research may find that tablets indeed allow for increased recall of certain kinds of website content.
ContributorsRaines, David Thomas (Author) / Martin, Judith (Thesis director) / Johnson, Kathryn (Committee member) / Wiedmaier, Benjamin (Committee member) / Barrett, The Honors College (Contributor) / Hugh Downs School of Human Communication (Contributor) / Department of Psychology (Contributor)
Created2013-05
Description

Building on research on family communication and forgiveness, this study seeks to understand how families communicate the value and practice of forgiveness. Through semi-structured interviews, the study asks participants to recall their formative conversations and experiences about forgiveness with their family members and to discuss how those conversations influenced their

Building on research on family communication and forgiveness, this study seeks to understand how families communicate the value and practice of forgiveness. Through semi-structured interviews, the study asks participants to recall their formative conversations and experiences about forgiveness with their family members and to discuss how those conversations influenced their current perspectives on forgiveness. Interviews from five female undergraduate students yielded seven main themes from where individuals learn how to forgive: 1) Sibling conflicts, 2) Family conversations about friendship conflicts, 3) Conversations with Mom, 4) Living by example, 5) Take the high road, 6) “Life’s too short”, and 7) Messages rooted in faith and morality.

ContributorsPrivatsky, Madysen Mae (Author) / Edson, Belle (Thesis director) / Kloeber, Dayna (Committee member) / Hugh Downs School of Human Communication (Contributor) / Watts College of Public Service & Community Solut (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

The media often portrays and the public often percieves white women and women of color politicians experience feminist obstacles, such as the masculine-feminine double bind and being dehumanized in the same way. Many of these representations of women of color politicians in society do not incorporate the impact of intersectionality

The media often portrays and the public often percieves white women and women of color politicians experience feminist obstacles, such as the masculine-feminine double bind and being dehumanized in the same way. Many of these representations of women of color politicians in society do not incorporate the impact of intersectionality and confining gender schemas; therefore, women of color politician’s experiences are often lumped together with that of their white women counterparts. This phenomenon ultimately contributes to the persistence of color-blind racism in the United States, which negatively effects the life outcomes of women of color politicians and women of color in general. In effort to help lessen the effects of color-blind racism locally and in government, some tools on how to reflect on one’s own biases are provided and avenues for change are proposed.

ContributorsCook, Caroline Matie (Author) / Sturgess, Jessica (Thesis director) / O'Flaherty, Katherine (Committee member) / Hugh Downs School of Human Communication (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05