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141.
DNA intercalators bind nucleic acids by stacking between adjacent basepairs. This causes a considerable elongation of the DNA backbone as well as untwisting of the double helix. In the past few years, single-molecule mechanical experiments have become a common tool to characterize these deformations and to quantify important parameters of the intercalation process. Parameter extraction typically relies on the neighbor-exclusion model, in which a bound intercalator prevents intercalation into adjacent sites. Here, we challenge the neighbor-exclusion model by carefully quantifying and modeling the force-extension and twisting behavior of single ethidium-complexed DNA molecules. We show that only an anticooperative ethidium binding that allows for a disfavored but nonetheless possible intercalation into nearest-neighbor sites can consistently describe the mechanical behavior of intercalator-bound DNA. At high ethidium concentrations and elevated mechanical stress, this causes an almost complete occupation of nearest-neighbor sites and almost a doubling of the DNA contour length. We furthermore show that intercalation into nearest-neighbor sites needs to be considered when estimating intercalator parameters from zero-stress elongation and twisting data. We think that the proposed anticooperative binding mechanism may also be applicable to other intercalating molecules. 相似文献
142.
Ralf Buettner Le Xuan Truong Nguyen Bijender Kumar Corey Morales Chao Liu Lisa S. Chen Tea Pemovska Timothy W. Synold Joycelynne Palmer Ryan Thompson Ling Li Dinh Hoa Hoang Bin Zhang Lucy Ghoda Claudia Kowolik Mika Kontro Calum Leitch Krister Wennerberg Xiaochun Yu Ching-Cheng Chen David Horne Varsha Gandhi Vinod Pullarkat Guido Marcucci Steven T. Rosen 《Journal of cellular physiology》2019,234(9):16295-16303
143.
Medinets Sergiy Gasche Rainer Kiese Ralf Rennenberg Heinz Butterbach-Bahl Klaus 《Plant and Soil》2019,445(1-2):335-348
Plant and Soil - Soils are known to be significant sources of atmospheric nitric oxide (NO), a key compound in atmospheric chemistry. NO is a key regulating substance for inter- and intra-species... 相似文献
144.
Genome-Wide Analysis of Alternative Splicing in Zea mays during Maize Iranian Mosaic Virus Infection
Ghorbani Abozar Tahmasebi Ahmad Izadpanah Keramatollah Afsharifar Alireza Dietzgen Ralf G. 《Plant Molecular Biology Reporter》2019,37(5-6):413-420
Plant Molecular Biology Reporter - Maize Iranian mosaic virus (MIMV) infects several gramineous plants and is an economically important nucleorhabdovirus in Iran. Maize responds to MIMV infection... 相似文献
145.
Santos Gleice S. Stemmann Lars Lombard Fabien Schwamborn Ralf 《Coral reefs (Online)》2019,38(6):1107-1120
Coral Reefs - In spite of the paramount ecological and socioeconomic relevance of tropical reef ecosystems, the dynamics of their meroplankton abundance remain poorly characterized. The small-scale... 相似文献
146.
147.
Grote R Li L Tamaoka J Kato C Horikoshi K Antranikian G 《Extremophiles : life under extreme conditions》1999,3(1):55-62
A novel coccoid-shaped, hyperthermophilic, anaerobic archaeon, strain RG-20, was isolated from a deep-sea hydrothermal vent
fluid sample taken at 1394-m depth at the Mid-Okinawa Trough (27°32.7′N, 126°58.5′E). Cells of this isolate occur singly or
in pairs and are about 0.8 to 2 μm in diameter. Growth was observed at temperatures between 50° and 93°C, with an optimum
at 85°C. The pH range for growth is 5.0–9.0, with an optimum around 7.0. Strain RG-20 requires 1%–4% of NaCl for growth, and
cell lysis occurs at concentrations below 1%. The newly isolated strain grows preferentially in the presence of elemental
sulfur on proteinaceous substrates such as yeast extract, peptone, or tryptone, and no growth was observed on carbohydrates,
carboxylic acids, alcohols, or lipids. This microorganism is resistant to streptomycin, chloramphenicol, ampicillin, and kanamycin
at concentrations up to 150 μg/ml, but is susceptible to rifampicin. Analysis of the hydrolyzed core lipids by thin-layer
chromatography (TLC) revealed the presence of archaeol and caldarchaeol. The mol% G+C content of the DNA is 55.8. Partial
sequencing of the 16S rDNA indicates that strain RG-20 belongs to the genus Thermococcus. Considering these data and on the basis of the results from DNA-DNA hybridization studies, we propose that this strain should
be classified as a new species named Thermococcus siculi (si′cu.li. L. gen. n. siculi, of the deep-sea [siculum, deep-sea in literature of Ovid], referring to the location of the sample site, a deep-sea hydrothermal vent). The type strain
is isolate RG-20 (DSM No. 12349).
Received: May 11, 1998 / Accepted: July 24, 1998 相似文献
148.
Inhibitors that are structurally related to the transition-state model of the proposed SN1-type mechanism of sialyl transfer, exhibit particularly high binding affinities to alpha(2-6)sialyltransferases. Furthermore, replacing the neuraminyl residue with a simple aryl or hetaryl ring and substituting the carboxylate group for a phosphonate moiety, improves both binding affinity and synthetic accessibility. Herein we report on the synthesis and inhibition of a wide range of novel, potent transition-state analogue based alpha(2-6)sialyltransferase inhibitors comprising a planar anomeric carbon, an increased distance between the anomeric carbon and the CMP leaving group, and at least two negative charges. We also present a short, efficient asymmetric synthesis of the most promising benzyl inhibitors, providing rapid access to large quantities of highly potent, stereochemically-pure (>96% de) inhibitors for further biological investigation (e.g.(R)-3b, Ki = 70 nM). 相似文献
149.
Published in 2003.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
150.