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Airich LG Tsyrenzhapova IS Vorontsova OV Feofanov AV Doroshenko VG Mashko SV 《Journal of molecular microbiology and biotechnology》2010,19(4):189-197
YddG is an inner membrane protein (IMP) that exports aromatic amino acids in Escherichia coli. Topology models of YddG produced by sequence-based analysis in silico have predicted the presence of 9 or 10 potential transmembrane segments. To experimentally analyze the membrane topology of YddG, we used randomly created fusions to β-lactamase (BlaM) as a reporter. The selection of such fusions under 50 μg/ml of ampicillin had to fit with the periplasmic location of the BlaM domain. Five periplasmic loops of YddG predicted by the 10-transmembrane (TM) helices model were identified via the characterization of 12 unique in-frame fusions distributed along the yddG coding region. To confirm the 10-TM helices model further, cytoplasmic regions of YddG were identified with the help of ZsGreen fluorescent protein as a reporter. The presence of four cytoplasmic regions and the cytoplasmic localization of the C-terminus were revealed. Therefore, a 10-TM helices topology with cytoplasmic locations of the N- and C-termini is supported. The present data confirm the 'positive-inside rule' for IMPs and the early results of other workers regarding the cytoplasmic location of the C-terminus of YddG. The pole-specific localization of YddG-ZsGreen in E. coli cells was detected by fluorescence microscopy. 相似文献
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Background
The statistical modeling of biomedical corpora could yield integrated, coarse-to-fine views of biological phenomena that complement discoveries made from analysis of molecular sequence and profiling data. Here, the potential of such modeling is demonstrated by examining the 5,225 free-text items in the Caenorhabditis Genetic Center (CGC) Bibliography using techniques from statistical information retrieval. Items in the CGC biomedical text corpus were modeled using the Latent Dirichlet Allocation (LDA) model. LDA is a hierarchical Bayesian model which represents a document as a random mixture over latent topics; each topic is characterized by a distribution over words. 相似文献4.
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Eshinimaev BTs Tsyrenzhapova IS Khmelenina VN Trotsenko IuA 《Prikladnaia biokhimiia i mikrobiologiia》2007,43(2):215-218
Detection and quantitative analysis of ectoine in bacterial biomass were performed by normal-phase high performance liquid chromatography with ultraviolet detection at 230 nm. Quantitative analysis was not hindered by glutamate and sucrose accumulation in bacteria. Measurement of ectoine concentration in haloalkaliphilic methanotrophs Methylobacter marinus 7C and Methylomicrobium alcaliphilum 5S showed that ectoine accumulation reached maximum (5 and 12% of dry cell weight) in the presence of NaCl at concentrations of 4 and 6%, respectively. 相似文献
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B. Ts. Eshinimaev I. S. Tsyrenzhapova V. N. Khmelenina Yu. A. Trotsenko 《Applied Biochemistry and Microbiology》2007,43(2):193-196
Detection and quantitative analysis of ectoine in bacterial biomass were performed by normal-phase high performance liquid chromatography with ultraviolet detection at 230 nm. Quantitative analysis was not hindered by glutamate and sucrose accumulation in bacteria. Measurement of ectoine concentration in haloalkaliphilic methanotrophs Methylobacter marinus 7C and Methylomicrobium alcaliphilum 5S showed that ectoine accumulation reached maximum (5 and 12% of dry cell weight) in the presence of NaCl at concentrations of 4 and 6%, respectively. 相似文献
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Gaĭnutdinova EA Eshinimaev BTs Tsyrenzhapova IS Dagurova OP Suzina NE Khmelenina VN Namsaraev BB Trotsenko IuA 《Mikrobiologiia》2005,74(4):562-571
The results of the first methodical investigation into the aerobic methanotrophic communities inhabiting the bottom sediments of Lake Baikal are reported. Use of the radioisotopic method revealed methane consumption in 12 10- to 50-cm-long sediment cores. The maximum methane consumption rates (495-737 microl/(dm3 day) were recorded in sediments in the regions of hydrothermal vents and oil and gas occurrence. Methane consumption was most active in the surface layers of the sediments (0-4 cm); it decreased with the sediment depth and became negligible or absent at depths below 20 cm. The number of methanotrophic bacteria usually ranged from 100 to 1000 cells/cm3 of sediment and reached 1 million cells/cm3 in the regions of oil and gas occurrence. The 17 enrichment cultures obtained were represented mainly by morphotype II methanotrophs. Phylogenetic analysis of the enrichment cultures in terms of the amino acid sequence of the alpha subunit of the membrane-bound methane monooxygenase revealed the predominance of methanotrophs of the genus Methylocystis. The results obtained suggest the presence of an active aerobic methanotrophic community in Lake Baikal. 相似文献
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Estimating the rate of evolution of the rate of molecular evolution 总被引:35,自引:13,他引:22
A simple model for the evolution of the rate of molecular evolution is
presented. With a Bayesian approach, this model can serve as the basis for
estimating dates of important evolutionary events even in the absence of
the assumption of constant rates among evolutionary lineages. The method
can be used in conjunction with any of the widely used models for
nucleotide substitution or amino acid replacement. It is illustrated by
analyzing a data set of rbcL protein sequences.
相似文献
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Vipond C Mulloy B Rigsby P Burkin K Bolgiano B;the MenC IS Working Group 《Biologicals》2012,40(5):353-363
Meningococcal group C (MenC) plain polysaccharide (PS) and conjugate vaccines are primarily evaluated by physicochemical methods to ensure that batches are consistently manufactured. As different assays are employed to quantify the MenC PS content of final formulations and bulk intermediaries, there is a need for an International MenC PS Standard to calibrate internal references used in the different laboratories. Twelve laboratories from nine different countries participated in a collaborative study to determine the MenC PS content of a candidate International Standard MenC PS preparation (08/214) and to assess its suitability. On the basis of the results from this study the candidate standard 08/214 was established as an International Standard for the quantification of MenC PS content in vaccines and components. It has a content of 1.192 ± 0.192 mg MenC PS/ampoule (expanded uncertainty with coverage factor of k = 2.365 corresponding to a 95% level of confidence), as determined by the resorcinol assays carried out by eight of the participating laboratories. The standard is available from The National Institute of Biological Standards and Control who act as guardians and distributors of the material under the auspices of WHO. 相似文献
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