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EA Dukhanina TI Lukyanova EA Romanova V Guerriero NV Gnuchev GP Georgiev DV Yashin LP Sashchenko 《Cell cycle (Georgetown, Tex.)》2015,14(22):3635-3643
PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4+ and CD8+ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response. 相似文献
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Ublinskaya AA Samsonov VV Mashko SV Stoynova NV 《Journal of microbiological methods》2012,89(3):167-173
The genetic manipulation of cells is the most promising strategy for designing microorganisms with desired traits. The most widely used approaches for integrating specific DNA-fragments into the Escherichia coli genome are based on bacteriophage site-specific and Red/ET-mediated homologous recombination systems. Specifically, the recently developed Dual In/Out integration strategy enables the integration of DNA fragments directly into specific chromosomal loci (Minaeva et al., 2008). To develop this strategy further, we designed a method for the precise cloning of any long DNA fragments from the E. coli chromosome and their targeted insertion into the genome that does not require PCR. In this method, the region of interest is flanked by I-SceI rare-cutting restriction sites, and the I-SceI-bracketed region is cloned into the unique I-SceI site of an integrative plasmid vector that then enables its targeted insertion into the E. coli chromosome via bacteriophage φ80 Int-mediated specialized recombination. This approach allows any long specific DNA fragment from the E. coli genome to be cloned without a PCR amplification step and reproducibly inserted into any chosen chromosomal locus. The developed method could be particularly useful for the construction of marker-less and plasmid-less recombinant strains in the biotechnology industry. 相似文献
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Acevedo A Stoynova L Davis K Solórzano R Collins ED 《The Journal of steroid biochemistry and molecular biology》2004,(1-5):83-87
Most of the actions of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] are mediated by binding to the Vitamin D nuclear receptor (VDR). The crystal structure of a deletion mutant (Delta165-215) of the VDR ligand-binding domain (LBD) bound to 1,25(OH)(2)D(3) indicates that amino acid residues tyrosine-143 and serine-278 form hydrogen bonding interactions with the 3-hydroxyl group of 1,25(OH)(2)D(3). Studies of VDR and three mutants (Y143F, S278A, and Y143F/S278A) did not indicate any differences in the binding affinity between the variant receptors and the wild-type receptor. This might indicate that the 3-hydroxyl group binds differently to the full-length VDR than the to deletion mutant. To further investigate, four deletion VDR mutants were constructed: VDR(Delta165-215), VDR(Delta165-215) (Y143F), VDR(Delta165-215) (S278A), VDR(Delta165-215) (Y143F/S278A). There were no significant differences in binding affinity between the wild-type receptor and the deletion mutants except for VDR(Delta165-215) (Y143F/S278A). In gene activation assays, VDR constructs with the single mutation Y143F and the double mutation Y143F/S278A, but not the single mutation S278A required higher doses of 1,25(OH)(2)D(3) for half-maximal response. This suggests that there are some minor structural and functional differences between the wild-type VDR and the Delta165-215 deletion mutant and that Y143 residue is more important for receptor function than residue S278. 相似文献
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E. V. Sycheva T. A. Yampol’skaya E. S. Preobrajenskaya A. E. Novikova N. G. Matrosov N. V. Stoynova 《Microbiology》2007,76(6):712-718
Overproduction of noncanonical amino acids norvaline and norleucine by Escherichia coli with inactivated acetohydroxy acid synthases was demonstrated. The cultivation conditions for the overproduction of noncanonical amino acids were studied. The effect of the restoration of acetohydroxy acid synthase activity, increased expression of the leuABCD operon, and inactivation of the biosynthetic threonine deaminase on norvaline and norleucine synthesis was studied. When grown under valine limitation, E. coli cells with inactivated acetohydroxy acid synthases and an elevated level of expression of the valine operon were shown to accumulate norvaline and norleucine (up to 0.8 and 4 g/l, respectively). These results confirm the existing hypothesis of norvaline and norleucine formation from 2-ketobutyrate by leucine biosynthesis enzymes. 相似文献
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Akhverdyan VZ Gak ER Tokmakova IL Stoynova NV Yomantas YA Mashko SV 《Applied microbiology and biotechnology》2011,91(4):857-871
The advantages of phage Mu transposition-based systems for the chromosomal editing of plasmid-less strains are reviewed. The
cis and trans requirements for Mu phage-mediated transposition, which include the L/R ends of the Mu DNA, the transposition factors MuA
and MuB, and the cis/trans functioning of the E element as an enhancer, are presented. Mini-Mu(LR)/(LER) units are Mu derivatives that lack most of
the Mu genes but contain the L/R ends or a properly arranged E element in cis to the L/R ends. The dual-component system, which consists of an integrative plasmid with a mini-Mu and an easily eliminated
helper plasmid encoding inducible transposition factors, is described in detail as a tool for the integration/amplification
of recombinant DNAs. This chromosomal editing method is based on replicative transposition through the formation of a cointegrate
that can be resolved in a recombination-dependent manner. (E-plus)- or (E-minus)-helpers that differ in the presence of the
trans-acting E element are used to achieve the proper mini-Mu transposition intensity. The systems that have been developed for
the construction of stably maintained mini-Mu multi-integrant strains of Escherichia coli and Methylophilus methylotrophus are described. A novel integration/amplification/fixation strategy is proposed for consecutive independent replicative transpositions
of different mini-Mu(LER) units with “excisable” E elements in methylotrophic cells. 相似文献
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Savrasova EA Kivero AD Shakulov RS Stoynova NV 《Journal of industrial microbiology & biotechnology》2011,38(9):1287-1294
Microbiological synthesis of higher alcohols (1-butanol, isobutanol, 2-methyl-1-butanol, etc.) from plant biomass is critically
important due to their advantages over ethanol as a motor fuel. In recent years, the use of branched-chain amino acid (BCAA)
biosynthesis pathways together with heterologous Ehrlich pathway enzyme system (Hazelwood et al. in Appl Environ Microbiol
74:2259–2266, 2008) has been proposed by the Liao group as an alternative approach to aerobic production of higher alcohols
as new-generation biofuels (Atsumi et al. in Nature 451:86–90, 2008; Atsumi et al. in Appl Microbiol Biotechnol 85:651–657,
2010; Cann and Liao in Appl Microbiol Biotechnol 81:89–98, 2008; Connor and Liao in Appl Environ Microbiol 74:5769–5775, 2008;
Shen and Liao in Metab Eng 10:312–320, 2008; Yan and Liao in J Ind Microbiol Biotechnol 36:471–479, 2009). On the basis of
these remarkable investigations, we re-engineered Escherichia coli valine-producing strain H-81, which possess overexpressed ilvGMED operon, for the aerobic conversion of sugar into isobutanol. To redirect valine biosynthesis to the production of alcohol,
we also—as has been demonstrated previously (Atsumi et al. in Nature 451:86–90, 2008; Atsumi et al. in Appl Microbiol Biotechnol
85:651–657, 2010; Cann and Liao in Appl Microbiol Biotechnol 81:89–98, 2008; Connor and Liao in Appl Environ Microbiol 74:5769–5775,
2008; Shen and Liao in Metab Eng 10:312–320, 2008; Yan and Liao in J Ind Microbiol Biotechnol 36:471–479, 2009)—used enzymes
of Ehrlich pathway. In particular, in our study, the following heterologous proteins were exploited: branched-chain 2-keto
acid decarboxylase (BCKAD) encoded by the kdcA gene from Lactococcus lactis with rare codons substituted, and alcohol dehydrogenase (ADH) encoded by the ADH2 gene from Saccharomyces cerevisiae. We show that expression of both of these genes in the valine-producing strain H-81 results in accumulation of isobutanol
instead of valine. Expression of BCKAD alone also resulted in isobutanol accumulation in the culture broth, supporting earlier
obtained data (Atsumi et al. in Appl Microbiol Biotechnol 85:651–657, 2010) that native ADHs of E. coli are also capable of isobutanol production. Thus, in this work, isobutanol synthesis by E. coli was achieved using enzymes similar to but somewhat different from those previously used. 相似文献
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We present an efficient computational architecture designed using supervised machine learning model to predict amyloid fibril
forming protein segments, named AmylPepPred. The proposed prediction model is based on bio-physio-chemical properties of
primary sequences and auto-correlation function of their amino acid indices. AmylPepPred provides a user friendly web interface
for the researchers to easily observe the fibril forming and non-fibril forming hexmers in a given protein sequence. We expect that
this stratagem will be highly encouraging in discovering fibril forming regions in proteins thereby benefit in finding therapeutic
agents that specifically aim these sequences for the inhibition and cure of amyloid illnesses.