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排序方式: 共有1596条查询结果,搜索用时 15 毫秒
111.
Mitch R. Lindquist Juan Carlos López-Núñez Marjorie A. Jones Elby J. Cox Rebecca J. Pinkelman Sookie S. Bang Bryan R. Moser Michael A. Jackson Loren B. Iten Cletus P. Kurtzman Kenneth M. Bischoff Siqing Liu Nasib Qureshi Kenneth Tasaki Joseph O. Rich Michael A. Cotta Badal C. Saha Stephen R. Hughes 《Applied microbiology and biotechnology》2015,99(22):9723-9743
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We describe the generation of a family of high-signal-to-noise single-wavelength genetically encoded indicators for maltose. This was achieved by insertion of circularly permuted fluorescent proteins into a bacterial periplasmic binding protein (PBP), Escherichia coli maltodextrin-binding protein, resulting in a four-color family of maltose indicators. The sensors were iteratively optimized to have sufficient brightness and maltose-dependent fluorescence increases for imaging, under both one- and two-photon illumination. We demonstrate that maltose affinity of the sensors can be tuned in a fashion largely independent of the fluorescent readout mechanism. Using literature mutations, the binding specificity could be altered to moderate sucrose preference, but with a significant loss of affinity. We use the soluble sensors in individual E. coli bacteria to observe rapid maltose transport across the plasma membrane, and membrane fusion versions of the sensors on mammalian cells to visualize the addition of maltose to extracellular media. The PBP superfamily includes scaffolds specific for a number of analytes whose visualization would be critical to the reverse engineering of complex systems such as neural networks, biosynthetic pathways, and signal transduction cascades. We expect the methodology outlined here to be useful in the development of indicators for many such analytes. 相似文献
115.
BAX, the BCL-2-associated X protein, is a cardinal proapoptotic member of the BCL-2 family, which regulates the critical balance between cellular life and death. Because so many medical conditions can be categorized as diseases of either too many or too few cells, dissecting the biochemistry of BCL-2 family proteins and developing pharmacological strategies to target them have become high priority scientific objectives. Here, we focus on BAX, a latent, cytosolic and monomeric protein that transforms into a lethal mitochondrial oligomer in response to cellular stress. New insights into the structural location of BAX's 'on switch', and the multi-step conformational changes that ensue upon BAX activation, are providing fresh opportunities to modulate BAX for potential benefit in human diseases characterized by pathologic cell survival or unwanted cellular demise. 相似文献
116.
Frances L. Chadbourne Catriona Raleigh Hayder Z. Ali Paul W. Denny Steven L. Cobb 《Journal of peptide science》2011,17(11):751-755
Given the paucity and toxicity of available drugs for leishmaniasis, coupled with the advent of drug resistance, the discovery of new therapies for this neglected tropical disease is recognised as being of the utmost urgency. As such antimicrobial peptides (AMPs) have been proposed as promising compounds against the causative Leishmania species, insect vector‐borne protozoan parasites. Here the AMP temporins A, B and 1Sa have been synthesised and screened for activity against Leishmania mexicana insect stage promastigotes and mammalian stage amastigotes, a significant cause of human cutaneous disease. In contrast to previous studies with other species the activity of these AMPs against L. mexicana amastigotes was low. This suggests that amastigotes from different Leishmania species display varying susceptibility to peptides from the temporin family, perhaps indicating differences in their surface structure, the proposed target of these AMPs. In contrast, insect stage L. mexicana promastigotes were sensitive to two of the screened temporins which clearly demonstrates the importance of screening AMPs against both forms of the parasite. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
117.
Long-Term Tree Cover Dynamics in a Pinyon-Juniper Woodland: Climate-Change-Type Drought Resets Successional Clock 总被引:1,自引:0,他引:1
Woody vegetation has expanded in coverage over the past century in many places globally, exemplified by pinyon-juniper changes
in the Southwestern United States. Extreme drought is one of the few non-management drivers besides fire that might reverse
such cover changes, but this has not been well documented. Here, we assess 68 years of tree cover dynamics across an elevation
gradient of a pinyon-juniper woodland using aerial photographs (1936 and 1959) and QuickBird imagery (2004). Canopy cover
increased 32% from 1936 to the onset of a major drought (2002). The largest relative increase in canopy cover occurred from
1936 to 1959 at the higher elevations, but these gains were eliminated by fires occurring from 1959 to 2002, during which
time lower elevations with low canopy cover exhibited the greatest relative increases. The 2002–2004 drought reduced canopy
cover by 55%, which eliminated gains in cover that occurred since 1936. Relative tree cover loss was highest at low elevations
with low tree cover, but absolute tree cover loss was greater in areas of high tree cover, which increased with elevation.
The loss of more than half of the canopy cover during a 2-year drought period was much greater than losses due to fire or
possible increases due to historic land use (for example, grazing). These results suggest that regional-scale climatic influences
may be more important than land use legacies in controlling tree cover of these and perhaps other semiarid woodlands over
longer time scales—notable given that similar episodes of tree mortality are projected in coming decades with climate change. 相似文献
118.
Anderson I Risso C Holmes D Lucas S Copeland A Lapidus A Cheng JF Bruce D Goodwin L Pitluck S Saunders E Brettin T Detter JC Han C Tapia R Larimer F Land M Hauser L Woyke T Lovley D Kyrpides N Ivanova N 《Standards in genomic sciences》2011,5(1):50-60
Ferroglobus placidus belongs to the order Archaeoglobales within the archaeal phylum Euryarchaeota. Strain AEDII12DO is the type strain of the species and was isolated from a shallow marine hydrothermal system at Vulcano, Italy. It is a hyperthermophilic, anaerobic chemolithoautotroph, but it can also use a variety of aromatic compounds as electron donors. Here we describe the features of this organism together with the complete genome sequence and annotation. The 2,196,266 bp genome with its 2,567 protein-coding and 55 RNA genes was sequenced as part of a DOE Joint Genome Institute Laboratory Sequencing Program (LSP) project. 相似文献
119.
Copeland A O'Connor K Lucas S Lapidus A Berry KW Detter JC Del Rio TG Hammon N Dalin E Tice H Pitluck S Bruce D Goodwin L Han C Tapia R Saunders E Schmutz J Brettin T Larimer F Land M Hauser L Vargas C Nieto JJ Kyrpides NC Ivanova N Göker M Klenk HP Csonka LN Woyke T 《Standards in genomic sciences》2011,5(3):379-388
Chromohalobacter salexigens is one of nine currently known species of the genus Chromohalobacter in the family Halomonadaceae. It is the most halotolerant of the so-called 'moderately halophilic bacteria' currently known and, due to its strong euryhaline phenotype, it is an established model organism for prokaryotic osmoadaptation. C. salexigens strain 1H11(T) and Halomonas elongata are the first and the second members of the family Halomonadaceae with a completely sequenced genome. The 3,696,649 bp long chromosome with a total of 3,319 protein-coding and 93 RNA genes was sequenced as part of the DOE Joint Genome Institute Program DOEM 2004. 相似文献
120.
Chertkov O Brown PJ Kysela DT de Pedro MA Lucas S Copeland A Lapidus A Del Rio TG Tice H Bruce D Goodwin L Pitluck S Detter JC Han C Larimer F Chang YJ Jeffries CD Land M Hauser L Kyrpides NC Ivanova N Ovchinnikova G Tindall BJ Göker M Klenk HP Brun YV 《Standards in genomic sciences》2011,5(3):287-297
The family Hyphomonadaceae within the Alphaproteobacteria is largely comprised of bacteria isolated from marine environments with striking morphologies and an unusual mode of cell growth. Here, we report the complete genome sequence Hirschia baltica, which is only the second a member of the Hyphomonadaceae with a published genome sequence. H. baltica is of special interest because it has a dimorphic life cycle and is a stalked, budding bacterium. The 3,455,622 bp long chromosome and 84,492 bp plasmid with a total of 3,222 protein-coding and 44 RNA genes were sequenced as part of the DOE Joint Genome Institute Program CSP 2008. 相似文献