排序方式: 共有22条查询结果,搜索用时 15 毫秒
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Lunin VV Dobrovetsky E Khutoreskaya G Zhang R Joachimiak A Doyle DA Bochkarev A Maguire ME Edwards AM Koth CM 《Nature》2006,440(7085):833-837
The magnesium ion, Mg2+, is essential for myriad biochemical processes and remains the only major biological ion whose transport mechanisms remain unknown. The CorA family of magnesium transporters is the primary Mg2+ uptake system of most prokaryotes and a functional homologue of the eukaryotic mitochondrial magnesium transporter. Here we determine crystal structures of the full-length Thermotoga maritima CorA in an apparent closed state and its isolated cytoplasmic domain at 3.9 A and 1.85 A resolution, respectively. The transporter is a funnel-shaped homopentamer with two transmembrane helices per monomer. The channel is formed by an inner group of five helices and putatively gated by bulky hydrophobic residues. The large cytoplasmic domain forms a funnel whose wide mouth points into the cell and whose walls are formed by five long helices that are extensions of the transmembrane helices. The cytoplasmic neck of the pore is surrounded, on the outside of the funnel, by a ring of highly conserved positively charged residues. Two negatively charged helices in the cytoplasmic domain extend back towards the membrane on the outside of the funnel and abut the ring of positive charge. An apparent Mg2+ ion was bound between monomers at a conserved site in the cytoplasmic domain, suggesting a mechanism to link gating of the pore to the intracellular concentration of Mg2+. 相似文献
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导读:自从微软购买SCO公司的Unix技术使用许可之后,Windows和Linux两种操作系统之间的争夺似乎有愈演愈烈之势。到底二者之间孰优孰劣,哪种更容易出现安全问题呢?《NewsFactor》网站就此撰写了一份特别报道,从各方业内分析师的角度帮助对两种操作系统的表现进行了对比和分析。 相似文献
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The mdx mouse diaphragm reproduces the degenerative changes of Duchenne muscular dystrophy 总被引:30,自引:0,他引:30
H H Stedman H L Sweeney J B Shrager H C Maguire R A Panettieri B Petrof M Narusawa J M Leferovich J T Sladky A M Kelly 《Nature》1991,352(6335):536-539
Although murine X-linked muscular dystrophy (mdx) and Duchenne muscular dystrophy (DMD) are genetically homologous and both characterized by a complete absence of dystrophin, the limb muscles of adult mdx mice suffer neither the detectable weakness nor the progressive degeneration that are features of DMD. Here we show that the mdx mouse diaphragm exhibits a pattern of degeneration, fibrosis and severe functional deficit comparable to that of DMD limb muscle, although adult mice show no overt respiratory impairment. Progressive functional changes include reductions in strength (to 13.5% of control by two years of age), elasticity, twitch speed and fibre length. The collagen density rises to at least seven times that of control diaphragm and ten times that of mdx hind-limb muscle. By 1.5 years of age, similar but less severe histological changes emerge in the accessory muscles of respiration. On the basis of these findings, we propose that dystrophin deficiency alters the threshold for work-induced injury. Our data provide a quantitative framework for studying the pathogenesis of dystrophy and extend the application of the mdx mouse as an animal model. 相似文献
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A framework for variation discovery and genotyping using next-generation DNA sequencing data 总被引:7,自引:0,他引:7
DePristo MA Banks E Poplin R Garimella KV Maguire JR Hartl C Philippakis AA del Angel G Rivas MA Hanna M McKenna A Fennell TJ Kernytsky AM Sivachenko AY Cibulskis K Gabriel SB Altshuler D Daly MJ 《Nature genetics》2011,43(5):491-498
Recent advances in sequencing technology make it possible to comprehensively catalog genetic variation in population samples, creating a foundation for understanding human disease, ancestry and evolution. The amounts of raw data produced are prodigious, and many computational steps are required to translate this output into high-quality variant calls. We present a unified analytic framework to discover and genotype variation among multiple samples simultaneously that achieves sensitive and specific results across five sequencing technologies and three distinct, canonical experimental designs. Our process includes (i) initial read mapping; (ii) local realignment around indels; (iii) base quality score recalibration; (iv) SNP discovery and genotyping to find all potential variants; and (v) machine learning to separate true segregating variation from machine artifacts common to next-generation sequencing technologies. We here discuss the application of these tools, instantiated in the Genome Analysis Toolkit, to deep whole-genome, whole-exome capture and multi-sample low-pass (~4×) 1000 Genomes Project datasets. 相似文献
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Sansone SA Rocca-Serra P Field D Maguire E Taylor C Hofmann O Fang H Neumann S Tong W Amaral-Zettler L Begley K Booth T Bougueleret L Burns G Chapman B Clark T Coleman LA Copeland J Das S de Daruvar A de Matos P Dix I Edmunds S Evelo CT Forster MJ Gaudet P Gilbert J Goble C Griffin JL Jacob D Kleinjans J Harland L Haug K Hermjakob H Ho Sui SJ Laederach A Liang S Marshall S McGrath A Merrill E Reilly D Roux M Shamu CE Shang CA Steinbeck C Trefethen A Williams-Jones B Wolstencroft K Xenarios I 《Nature genetics》2012,44(2):121-126
To make full use of research data, the bioscience community needs to adopt technologies and reward mechanisms that support interoperability and promote the growth of an open 'data commoning' culture. Here we describe the prerequisites for data commoning and present an established and growing ecosystem of solutions using the shared 'Investigation-Study-Assay' framework to support that vision. 相似文献
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Nugent PE Sullivan M Cenko SB Thomas RC Kasen D Howell DA Bersier D Bloom JS Kulkarni SR Kandrashoff MT Filippenko AV Silverman JM Marcy GW Howard AW Isaacson HT Maguire K Suzuki N Tarlton JE Pan YC Bildsten L Fulton BJ Parrent JT Sand D Podsiadlowski P Bianco FB Dilday B Graham ML Lyman J James P Kasliwal MM Law NM Quimby RM Hook IM Walker ES Mazzali P Pian E Ofek EO Gal-Yam A Poznanski D 《Nature》2011,480(7377):344-347
Type Ia supernovae have been used empirically as 'standard candles' to demonstrate the acceleration of the expansion of the Universe even though fundamental details, such as the nature of their progenitor systems and how the stars explode, remain a mystery. There is consensus that a white dwarf star explodes after accreting matter in a binary system, but the secondary body could be anything from a main-sequence star to a red giant, or even another white dwarf. This uncertainty stems from the fact that no recent type Ia supernova has been discovered close enough to Earth to detect the stars before explosion. Here we report early observations of supernova SN 2011fe in the galaxy M101 at a distance from Earth of 6.4 megaparsecs. We find that the exploding star was probably a carbon-oxygen white dwarf, and from the lack of an early shock we conclude that the companion was probably a main-sequence star. Early spectroscopy shows high-velocity oxygen that slows rapidly, on a timescale of hours, and extensive mixing of newly synthesized intermediate-mass elements in the outermost layers of the supernova. A companion paper uses pre-explosion images to rule out luminous red giants and most helium stars as companions to the progenitor. 相似文献