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731.
ISRm14 is 2695 basepairs (bp) in size and bordered by 22 bp imperfect inverted repeats (IRs). A 9-bp target sequence is duplicated
upon ISRm14 transposition. The DNA strand that putatively encodes the transposase enzyme carries three open reading frames (ORFs) designated
ORFs1 to 3, which specify putative proteins of 15.9 kDa, 13.1 kDa, and 61.1 kDa, respectively. According to its structural
characteristics, ISRm14 belongs to the recently proposed IS66 family of IS elements. The ORFs1 to 3 encoded putative proteins displayed significant similarities to ORFs of the previously
unrecognized IS element ISEc8, which is inserted adjacent to the locus of enterocyte effacement (LEE) pathogenicity island of Escherichia coli EDL933. Analyses of the distribution of ISRm14 in a natural S. meliloti population showed its widespread occurrence in 66% of the strains tested with a copy number ranging from 1 to 6.
Received: 13 May 1999 / Accepted: 14 June 1999 相似文献
732.
Kristien Peeters Ivan Litvinenko Bob Asselbergh Leonardo Almeida-Souza Teodora Chamova Thomas Geuens Elke Ydens Magdalena Zimoń Joy Irobi Els De?Vriendt Vicky De?Winter Tinne Ooms Vincent Timmerman Ivailo Tournev Albena Jordanova 《American journal of human genetics》2013,92(6):955-964
The most common form of spinal muscular atrophy (SMA) is a recessive disorder caused by deleterious SMN1 mutations in 5q13, whereas the genetic etiologies of non-5q SMA are very heterogeneous and largely remain to be elucidated. In a Bulgarian family affected by autosomal-dominant proximal SMA, we performed genome-wide linkage analysis and whole-exome sequencing and found a heterozygous de novo c.320C>T (p.Ser107Leu) mutation in bicaudal D homolog 2 (Drosophila) (BICD2). Further analysis of BICD2 in a cohort of 119 individuals with non-5q SMA identified a second de novo BICD2 mutation, c.2321A>G (p.Glu774Gly), in a simplex case. Detailed clinical and electrophysiological investigations revealed that both families are affected by a very similar disease course, characterized by early childhood onset, predominant involvement of lower extremities, and very slow disease progression. The amino acid substitutions are located in two interaction domains of BICD2, an adaptor protein linking the dynein molecular motor with its cargo. Our immunoprecipitation and localization experiments in HeLa and SH-SY5Y cells and affected individuals’ lymphoblasts demonstrated that p.Ser107Leu causes increased dynein binding and thus leads to accumulation of BICD2 at the microtubule-organizing complex and Golgi fragmentation. In addition, the altered protein had a reduced colocalization with RAB6A, a regulator of vesicle trafficking between the Golgi and the endoplasmic reticulum. The interaction between p.Glu744Gly altered BICD2 and RAB6A was impaired, which also led to their reduced colocalization. Our study identifies BICD2 mutations as a cause of non-5q linked SMA and highlights the importance of dynein-mediated motility in motor neuron function in humans. 相似文献
733.
734.
Floodplain forest ecosystems are highly valuable to society because of their potential for water quality improvement and vegetation
productivity, among many other functions. Previous studies have indicated that hydrology influences productivity but that
the relationship between hydroperiod and productivity is a complex one. Consequently, we compared multiple indexes of productivity,
nutrient circulation, and hydroperiod among three communities on the Flint River floodplain, Georgia, that differed in terms
of inundation frequency. We hypothesized that (a) the wettest community would have the lowest total net primary production
(NPP) values because of saturated soil conditions; (b) as wetness increases, nutrient circulation in litterfall would decrease
because of the hypothesized lower productivity in the wetter community; and (c) as wetness increases, internal translocation
would become more efficient. The study site was partitioned into three wetness types—somewhat poorly drained (SPD), intermediate
(I) and poorly drained (PD). We found that belowground biomass was greatest on the SPD, litterfall was similar for all three
sites, and that woody biomass current annual increment (CAI) was greatest in the PD community. However, when the three variables
were totaled for each site, the PD had the greatest NPP, thus disproving hypothesis (a). For hypothesis (b), we observed that
P content in litterfall, although not significant, followed the predicted trend; nitrogen (N) content displayed the opposite
pattern (PD > I > SPD). As wetness increased, internal translocation became more efficient for phosphorus (support for hypothesis
[c]), but the SPD community was more efficient at retranslocating N (contradiction of hypothesis [c]).
Received 19 June 2000; accepted 19 October 2000. 相似文献
735.
Rosanne M. Orr Florence I. Raynaud Phyllis M. Goddard Ian R. Judson Terry Beck Bob Bryant 《Nucleosides, nucleotides & nucleic acids》2013,32(7-9):1699-1702
Abstract G3139, an 18mer phosphorothioate (S-labeled), was administered to mice by single i.v. bolus or continuous S.C. infusion. The latter schedule resulted in reduced liver metabolism and urinary excretion together with greater tissue accumulation, in particular to the liver, kidney and bone marrow, probably reflecting the dose received. 相似文献
736.
Bob Scott 《Journal of biological inorganic chemistry》2008,13(2):317-317
737.
738.
739.
Rubn M Buey David Fernndez-Justel Gloria Gonzlez-Holgado Marta Martínez-Júlvez Adrin Gonzlez-Lpez Adrin Velzquez-Campoy Milagros Medina Bob B Buchanan Monica Balsera 《Plant physiology》2021,186(1):285
Thioredoxin reductases control the redox state of thioredoxins (Trxs)—ubiquitous proteins that regulate a spectrum of enzymes by dithiol–disulfide exchange reactions. In most organisms, Trx is reduced by NADPH via a thioredoxin reductase flavoenzyme (NTR), but in oxygenic photosynthetic organisms, this function can also be performed by an iron-sulfur ferredoxin (Fdx)-dependent thioredoxin reductase (FTR) that links light to metabolic regulation. We have recently found that some cyanobacteria, such as the thylakoid-less Gloeobacter and the ocean-dwelling green oxyphotobacterium Prochlorococcus, lack NTR and FTR but contain a thioredoxin reductase flavoenzyme (formerly tentatively called deeply-rooted thioredoxin reductase or DTR), whose electron donor remained undefined. Here, we demonstrate that Fdx functions in this capacity and report the crystallographic structure of the transient complex between the plant-type Fdx1 and the thioredoxin reductase flavoenzyme from Gloeobacter violaceus. Thereby, our data demonstrate that this cyanobacterial enzyme belongs to the Fdx flavin-thioredoxin reductase (FFTR) family, originally described in the anaerobic bacterium Clostridium pasteurianum. Accordingly, the enzyme hitherto termed DTR is renamed FFTR. Our experiments further show that the redox-sensitive peptide CP12 is modulated in vitro by the FFTR/Trx system, demonstrating that FFTR functionally substitutes for FTR in light-linked enzyme regulation in Gloeobacter. Altogether, we demonstrate the FFTR is spread within the cyanobacteria phylum and propose that, by substituting for FTR, it connects the reduction of target proteins to photosynthesis. Besides, the results indicate that FFTR acquisition constitutes a mechanism of evolutionary adaptation in marine phytoplankton such as Prochlorococcus that live in low-iron environments. 相似文献
740.