Here we developed methods to attach fluorescent beads to H. We previously described methods to immobilize cells on a glass surface to visualize rotation of archaella using fluorescent labeling 10. Toward measuring archaellar motor torque, we developed protocols to attach markers to add viscous friction to rotating archaella. Unexpectedly, the estimated work done in a single rotation was higher than the expected energy input that would come from the hexameric FlaI architecture, suggesting a model for the mechanism of archaellar motor rotation involving hydrolysis of more than one ATP molecule per FlaI subunit per full rotation. nm independent of rotation speeds between 0.5 and 30 Hz.We found that archaellar torque remains constant at 160 pN To gain insights into the molecular mechanism underlying how FlaI drives rotation, we developed methods to measure archaellar motor torque. Challenges manipulating motor load, however, prevented us from measuring torque. We previously characterized archaellar function in the model organism Halobacterium salinarum using advanced fluorescent microscopy 10. Despite these biochemical insights, however, little is known of the physics of archaellar rotation. Furthermore, no other archaellar components have been implicated as energy-transducing proteins, indicating that FlaI powers archaellar rotation alone, with a catalytic cycle involving sequential hydrolysis of six ATP molecules. FlaI has been shown to hydrolyze ATP 8, and although the associated FlaH has an ATP binding motif 9, there is no evidence that FlaH hydrolyzes ATP. It is also unclear whether FlaI is static relative to the cell body or whether it rotates relative to the cell body together with the archaellum. FlaI forms a hexamer 7, 8 that likely drives rotation, although it is unclear how FlaI generates torque. ![]() The core archaellar motor is composed of the transmembrane protein FlaJ, ATPase FlaI, and associated FlaH. Crucially, the archaellum is driven by ATP hydrolysis 6 instead of proton flux as in the bacterial motor. The mechanism of archaellar rotation, however, remains unclear, in part due to the lack of biophysical measurements that would constrain mechanistic models.Ĭomponents of the archaellar motor have been identified and biochemically characterized, providing the first steps to understand the mechanism of rotation 3. Recent structural and functional studies of protein components have begun to provide us a model of archaellar architecture 1, 3, 4, 5. Instead, the archaellum is evolutionarily related to bacterial type IV pili. Although the bacterial flagellum consists of >30 different proteins, the archaellum is built from as few as 7 proteins, none of which are homologous to flagellar proteins 2. Res.-Atmos, 124, 2774-2795 doi:10.Motile archaea swim using surface appendages called archaella (previously named “archaeal flagella”), which are thrust-generating rotating helical filaments analogous to bacterial flagella 1. Z*.: Estimation and Uncertainty Analysis of Secondary Organic Carbon Using One‐Year of Hourly Organic and Elemental Carbon Data. Adoption of Histbox in research publications: Yin, C.*, Deng, X., Zou, Y., Solmon, F., Li, F., and Deng, T.: Trend analysis of surface ozone at suburban Guangzhou, China, ., 695, 133880, doi: 10.1016/j.scitotenv.2019.133880, 2019 Wu, C*., Wu, D., and Yu, J. Z.: Quantifying black carbon light absorption enhancement with a novel statistical approach, Atmos. Please cite this paper if HistBox program is used in your publication: Wu, C., Wu, D., and Yu, J. HistBox is an Igor based program, which packed with lots of useful features for data analysis and graph plotting, with a special focus on histogram and box plot. That leads to the development of HistBox. Numerous existing generalized data visualization software had been widely used in the community, but a number of features are lacked to satisfy many specified research purposes in atmospheric science. ![]() Goal: HistBox is a handy tool to maximize the efficiency of data visualization in atmospheric science.
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