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101.
Candidatus "Scalindua brodae", sp. nov., Candidatus "Scalindua wagneri", sp. nov., two new species of anaerobic ammonium oxidizing bacteria 总被引:1,自引:0,他引:1
Schmid M Walsh K Webb R Rijpstra WI van de Pas-Schoonen K Verbruggen MJ Hill T Moffett B Fuerst J Schouten S Damsté JS Harris J Shaw P Jetten M Strous M 《Systematic and applied microbiology》2003,26(4):529-538
Anaerobic ammonium oxidation (anammox) is both a promising process in wastewater treatment and a long overlooked microbial physiology that can contribute significantly to biological nitrogen cycling in the world's oceans. Anammox is mediated by a monophyletic group of bacteria that branches deeply in the Planctomycetales. Here we describe a new genus and species of anaerobic ammonium oxidizing planctomycetes, discovered in a wastewater treatment plant (wwtp) treating landfill leachate in Pitsea, UK. The biomass from this wwtp showed high anammox activity (5.0 +/- 0.5 nmol/mg protein/min) and produced hydrazine from hydroxylamine, one of the unique features of anammox bacteria. Eight new planctomycete 16S rRNA gene sequences were present in the 16S rRNA gene clone library generated from the biomass. Four of these were affiliated to known anammox 16S rRNA gene sequences, but branched much closer to the root of the planctomycete line of descent. Fluorescence in situ hybridization (FISH) with oligonucleotide probes specific for these new sequences showed that two species (belonging to the same genus) together made up > 99% of the planctomycete population which constituted 20% of the total microbial community. The identification of these organisms as typical anammox bacteria was confirmed with electron microscopy and lipid analysis. The new species, provisionally named Candidatus "Scalindua brodae" and "Scalindua wagneri" considerably extend the biodiversity of the anammox lineage on the 16S rRNA gene level, but otherwise resemble known anammox bacteria. Simultaneously, another new species of the same genus, Candidatus "Scalindua sorokinii", was detected in the water column of the Black Sea, making this genus the most widespread of all anammox bacteria described so far. 相似文献
102.
Just say no: floral repressors help Arabidopsis bide the time 总被引:1,自引:0,他引:1
103.
Co-Permeability of 3H-Labeled Water and 14C-Labeled Organic Acids across Isolated Plant Cuticles : Investigating Cuticular Paths of Diffusion and Predicting Cuticular Transpiration 下载免费PDF全文
Penetration of 3H-labeled water (3H2O) and the 14C-labeled organic acids benzoic acid ([14C]BA), salicylic acid ([14C]SA), and 2,4-dichlorophenoxyacetic acid ([14C]2,4-D) were measured simultaneously in isolated cuticular membranes of Prunus laurocerasus L., Ginkgo biloba L., and Juglans regia L. For each of the three pairs of compounds (3H2O/[14C]BA, 3H2O/[14C]SA, and 3H2O/[14C]2,4-D) rates of cuticular water penetration were highly correlated with the rates of penetration of the organic acids. Therefore, water and organic acids penetrated the cuticles by the same routes. With the combination 3H2O/[14C]BA, co-permeability was measured with isolated cuticles of nine other plant species. Permeances of 3H2O of all 12 investigated species were highly correlated with the permeances of [14C]BA (r2 = 0.95). Thus, cuticular transpiration can be predicted from BA permeance. The application of this experimental method, together with the established prediction equation, offers the opportunity to answer several important questions about cuticular transport physiology in future investigations. 相似文献
104.
El Fitori J Kleeff J Giese NA Guweidhi A Bosserhoff AK Büchler MW Friess H 《Cancer cell international》2005,5(1):3
Background
Melanoma inhibitory activity (MIA) is a small secreted protein that interacts with extracellular matrix proteins. Its over-expression promotes the metastatic behavior of malignant melanoma, thus making it a potential prognostic marker in this disease. In the present study, the expression and functional role of MIA was analyzed in pancreatic cancer by quantitative real-time PCR (QRT-PCR), immunohistochemistry, immunoblot analysis and ELISA. To determine the effects of MIA on tumor cell growth and invasion, MTT cell growth assays and modified Boyden chamber invasion assays were used. 相似文献105.
The localization of cytoplasmic free calcium and a dihydropyridine (DHP) receptor, a putative calcium channel, was recorded
during the opposite graviresponses of tip-growing Chara rhizoids and Chara protonemata by using the calcium indicator Calcium Crimson and a fluorescently labeled dihydropyridine (FL-DHP). In upward
(negatively gravitropically) growing protonemata and downward (positively gravitropically) growing rhizoids, a steep Ca2+ gradient and DHP receptors were found to be symmetrically localized in the tip. However, the localization of the Ca2+ gradient and DHP receptors differed considerably during the gravitropic responses upon horizontal positioning of the two
cell types. During the graviresponse of rhizoids, a continuous bowing downward by differential flank growth, the Ca2+ gradient and DHP receptors remained symmetrically localized in the tip at the centre of growth. However, after tilting protonemata
into a horizontal position, there was a drastic displacement of the Ca2+ gradient and FL-DHP to the upper flank of the apical dome. This displacement occurred after the apical intrusion and sedimentation
of the statoliths but clearly before the change in the growth direction became evident. In protonemata, the reorientation
of the growth direction started with the appearence of a bulge on that site of the upper flank which was predicted by the
asymmetrically displaced Ca2+ gradient. With the upward shift of the cell tip, which is suggested to result from a statolith-induced displacement of the
growth centre, the Ca2+ gradient and DHP receptors became symmetrically relocalized in the apical dome. No major asymmetrical rearrangement was observed
during the following phase of gravitropic curvature which is characterized by slower rates of bending. Labeling with FL-DHP
was completely inhibited by a non-fluorescently labeled dihydropyridine. From these results it is suggested that FL-DHP labels
calcium channels in rhizoids and protonemata. In rhizoids, positive gravitropic curvature is caused by differential growth
limited to the opposite subapical flanks of the apical dome, a process which does not involve displacement of the growth centre,
the calcium gradient or calcium channels. In protonemata, however, it is proposed that a statolith-induced asymmetrical relocalization
of calcium channels and the Ca2+ gradient precedes, and might mediate, the rearrangement of the centre of growth, most likely by the displacement of the Spitzenk?rper,
to the upper flank, which results in the negative gravitropic reorientation of the growth direction.
Received: 13 February 1999 / Accepted: 25 June 1999 相似文献
106.
Proteins are involved in virtually every biological process and in order to function, it is necessary for these polypeptide chains to fold into the unique, native conformation. This folding process can take place rapidly. NMR line shape analyses and transverse relaxation measurements allow protein folding studies on a microsecond-to-millisecond time scale. Together with an overview of current achievements within this field, we present millisecond protein folding studies by NMR of the cold shock protein CspB from Bacillus subtilis. 相似文献
107.
Human METTL16 is a N6‐methyladenosine (m6A) methyltransferase that targets pre‐mRNAs and various non‐coding RNAs 下载免费PDF全文
Philipp Hackert Christof Lenz Henning Urlaub Claudia Höbartner Katherine E Sloan Markus T Bohnsack 《EMBO reports》2017,18(11):2004-2014
N6‐methyladenosine (m6A) is a highly dynamic RNA modification that has recently emerged as a key regulator of gene expression. While many m6A modifications are installed by the METTL3–METTL14 complex, others appear to be introduced independently, implying that additional human m6A methyltransferases remain to be identified. Using crosslinking and analysis of cDNA (CRAC), we reveal that the putative human m6A “writer” protein METTL16 binds to the U6 snRNA and other ncRNAs as well as numerous lncRNAs and pre‐mRNAs. We demonstrate that METTL16 is responsible for N6‐methylation of A43 of the U6 snRNA and identify the early U6 biogenesis factors La, LARP7 and the methylphosphate capping enzyme MEPCE as METTL16 interaction partners. Interestingly, A43 lies within an essential ACAGAGA box of U6 that base pairs with 5′ splice sites of pre‐mRNAs during splicing, suggesting that METTL16‐mediated modification of this site plays an important role in splicing regulation. The identification of METTL16 as an active m6A methyltransferase in human cells expands our understanding of the mechanisms by which the m6A landscape is installed on cellular RNAs. 相似文献
108.
Wan Yun Ho Jer-Cherng Chang Kenneth Lim Amaury Cazenave-Gassiot Aivi T. Nguyen Juat Chin Foo Sneha Muralidharan Ashley Viera-Ortiz Sarah J.M. Ong Jin Hui Hor Ira Agrawal Shawn Hoon Olubankole Aladesuyi Arogundade Maria J. Rodriguez Su Min Lim Seung Hyun Kim John Ravits Shi-Yan Ng Markus R. Wenk Edward B. Lee Greg Tucker-Kellogg Shuo-Chien Ling 《The Journal of cell biology》2021,220(9)
109.
110.