1,241 research outputs found

    Functional Unit of the RNA Polymerase II C-Terminal Domain Lies within Heptapeptide Pairs 

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    Unlike all other RNA polymerases, the largest subunit (RPB1) of eukaryotic DNA-dependent RNA polymerase II (RNAP II) has a C-terminal domain (CTD) comprising tandemly repeated heptapeptides with the consensus sequence Y-S-P-T-S-P-S. The tandem structure, heptad consensus, and most key functions of the CTD are conserved between yeast and mammals. In fact, all metazoans, fungi, and green plants examined to date, as well as the nearest protistan relatives of these multicellular groups, contain a tandemly repeated CTD. In contrast, the RNAP II largest subunits from many other eukaryotic organisms have a highly degenerate C terminus or show no semblance of the CTD whatsoever. The reasons for intense stabilizing selection on CTD structure in certain eukaryotes, and its apparent absence in others, are unknown. Here we demonstrate, through in vivo genetic complementation, that the essential functional unit of the yeast CTD is contained within pairs of heptapeptides. Insertion of a single alanine residue between diheptads has little phenotypic effect, while increasing the distance between diheptads produces a mostly quantitative effect on yeast cell growth. We further explore structural constraints on the CTD within an evolutionary context and propose selective mechanisms that could maintain a global tandem structure across hundreds of millions of years of eukaryotic evolution. Originally published Eukaryotic Cell, Vol. 3, No. 3, June 200

    Second Annual Idaho Public Policy Survey

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    The Second Annual Idaho Public Policy Survey was conducted December 3-8, 2016 and surveyed 1000 adults currently living in the state of Idaho. Respondents were asked about their attitudes concerning several key policy issues, including significant focus on revenue and spending, transportation, education, refugees, and energy and climate change. The survey sample was designed to be representative of all regions of the state and was administered on behalf of the School of Public Service by GS Strategy Group, a Boise-based polling firm. Statewide results have a margin of error of +/- 3.1

    Genome sequence of Acetomicrobium hydrogeniformans OS1

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    Acetomicrobium hydrogeniformans, an obligate anaerobe of the phylum Synergistetes, was isolated from oil production water. It has the unusual ability to produce almost 4 molecules H2/molecule glucose. The draft genome of A. hydrogeniformans OS1 (DSM 22491T) is 2,123,925 bp, with 2,068 coding sequences and 60 RNA genes

    Effect of New Zealand Blackcurrant Extract on Substrate Oxidation and Cycling Performance in Normobaric Hypoxia

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    Blackcurrant is high in anthocyanin content. We have shown enhanced whole-body fat oxidation and increased time trial performance during cycling, in addition to increased femoral artery diameter during a sustained submaximal isometric contraction of the m.quadriceps with intake of New Zealand blackcurrant (NZBC) extract in normobaric normoxia (Cook et al., 2015, 2017). The effect of blackcurrant on metabolic and physiological responses and performance during cycling in normobaric hypoxia are not known. PURPOSE: To examine the effect of NZBC extract on intensity-dependent physiological and metabolic responses and 16.1-km cycling time trial in trained cyclists in normobaric hypoxia. METHODS: The study used a double-blind randomized cross-over design. Eleven healthy men from cycling and triathlon clubs with at least 3 yrs experience and cycling 8-10 hr·wk−1 (age: 38±11 yrs, height: 179±4 cm, body mass: 76±8 kg, V̇O2max: 47±5 mL·kg−1·min−1, maximum power: 398±38 W, mean±SD) ingested NZBC extract (600 mg·day−1 containing 220 mg anthocyanins) or placebo (PL) for 7 days (washout 14 days). Participants performed bouts of 10 min at 45, 55 and 65% V̇O2max, using indirect calorimetry and blood sampling, followed by a 16.1 km timetrial on a SRM ergometer (SRM International, Germany). Participants were familiarized for the time-trial. All testing took place in a temperature controlled (15°C) normobaric hypoxic chamber set at an altitude of ~2500 m (15% FiO2) (TIS Services, Medstead, UK) in morning sessions. Data was analysed using paired t-tests. RESULTS: At each intensity, NZBC extract had no effect on metabolic and physiological responses (e.g. at 65% V̇O2max, heart rate - PL: 133±12, NZBC; 132±12 beats·min-1); fat oxidation - PL: 0.24±0.12, NZBC: 0.20±0.16 g·min-1; carbohydrate oxidation - PL: 2.34±0.42, NZBC: 2.48±0.35 g·min-1; lactate - PL: 1.37±0.45, NZBC: 1.56±0.57 mmol·L-1). No improvements in 16.1 km time-trial performance were observed (PL: 1685±92, NZBC: 1685±99 sec). CONCLUSION: Seven day intake of New Zealand blackcurrant extract does not change whole-body fat oxidation and 16.1 km time-trial performance during cycling in normobaric hypoxia

    Computing the Complete Gravitational Wavetrain from Relativistic Binary Inspiral

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    We present a new method for generating the nonlinear gravitational wavetrain from the late inspiral (pre-coalescence) phase of a binary neutron star system by means of a numerical evolution calculation in full general relativity. In a prototype calculation, we produce 214 wave cycles from corotating polytropes, representing the final part of the inspiral phase prior to reaching the ISCO. Our method is based on the inequality that the orbital decay timescale due to gravitational radiation is much longer than an orbital period and the approximation that gravitational radiation has little effect on the structure of the stars. We employ quasi-equilibrium sequences of binaries in circular orbit for the matter source in our field evolution code. We compute the gravity-wave energy flux, and, from this, the inspiral rate, at a discrete set of binary separations. From these data, we construct the gravitational waveform as a continuous wavetrain. Finally, we discuss the limitations of our current calculation, planned improvements, and potential applications of our method to other inspiral scenarios.Comment: 4 pages, 4 figure
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