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1.
Binding sites for three families of sequence-specific DNA-binding proteins, microE3, C/EBP, and OCT, are found in both the promoters and the intronic enhancer of the immunoglobulin heavy-chain gene. We have used a cotransfection system to investigate how proteins binding these sites may participate in enhancer-promoter interactions. Basic helix-loop-helix-zipper (BHLHZIP) proteins TFE3 and TFEB activate from a distance in this assay, but the basic zipper (BZIP) protein NF-IL6 and endogenous OCT-binding proteins do not. Our results suggest that remotely bound TFE3 is recruited to the initiation site by association with proximally bound TFE3; this interaction is mediated by the BHLHZIP domain and not by activation domains of TFE3. The BZIP domain of Ig/EBP lacks this activity, revealing an important functional difference between these structurally related dimerization domains. We also show that TFE3 can exist as a tetramer in solution and that tetramerization is determined by the HLHZIP domain. These data support a model in which protein-protein interactions between proximally and remotely bound TFE3 recruit TFE3 to the initiation site for activation. The IgH gene is the first example of a cellular gene in which proximal and distal binding sites are found for a protein capable of mediating enhancer-promoter interaction.  相似文献   
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Mn(II) and Co(II) complexes of methyl-(Z)−N′-carbamothioylcarbamohydrazonate Schiff base ligand were synthesized. The ligand and metal salts were taken in 2 : 1 stoichiometric ratio. All the synthesized complexes were characterized using elemental analysis, molar conductance, magnetic moment and various spectroscopic techniques (FT-IR, UV/VIS, EPR) techniques. Elemental and spectroscopic results verified bidentate donor nature of the ligand and octahedral geometry of all the complexes. The non-electrolytic nature of Mn(II) and Co(II) complexes were suggested by conductivity data analysis. In vitro antibacterial (E. coli and S. aureus) and antifungal (C. albicans and C. tropicalis) screening were achieved by employing agar well diffusion method which revealed better antimicrobial activity of Co(II) complexes than Mn(II) complexes. In silico SwissADME study predicted the drug-likeness probability of ligand and complexes. The interaction of two bacterial proteins (E. coli and S. aureus) with compounds was also analyzed using molecular docking study, which corroborate the in vitro analysis.  相似文献   
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Two thermostable enzymes produced by the thermophilic fungus Paecilomyces varioti, a chitinase and laminarinase, were used to isolate protoplasts of a thermophilic fungus, Malbranchea sulfurea. The frequency of protoplast regeneration observed (35%) was considerably higher than that obtained using commercial lytic enzymes.  相似文献   
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Most agricultural commodities are susceptible to Aspergillus sp. infestation and aflatoxin elaboration. A simple test-tube screening procedure using fresh coconut milk agar medium (CMAM), for identifying toxigenic strains of Aspergillus sp., based on u.v. fluorescence (365 nm) and visual detection has been proposed and evaluated.  相似文献   
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MsrA, an efflux pump belonging to ATP‐binding cassette (ABC) transporter family that conferred resistance to macrolides, was detected in Staphylococcus aureus strains. Herein, we report the isolation of phytoconstituents from Piper cubeba fruit methanol extract and investigated their efflux pump inhibitory potential against S. aureus MsrA pump. Four isolated compounds, viz. pellitorine, sesamin, piperic acid and tetrahydropiperine studied in combination with erythromycin in S. aureus RN4220, exhibited 2–8‐fold reduction in minimum inhibitory concentration (MIC) of erythromycin. Pellitorine and sesamin decreased MIC of erythromycin by 8‐fold. The real‐time fluorometry‐based efflux and accumulation studies of ethidium bromide (EtBr) on S. aureus RN4220 in the presence of these compounds showed reduced efflux and enhanced uptake, thus indicating inhibition of the efflux pump. Pellitorine showed significant post‐antibiotic effect of erythromycin. The results revealed that the primary mechanism of action of these compounds involves steady ATP production impairment.  相似文献   
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Plant Cell, Tissue and Organ Culture (PCTOC) - Jatropha curcas is an undomesticated crop and its plantations did not meet commercial expectation due to absence of high yielding commercial line with...  相似文献   
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International Journal of Peptide Research and Therapeutics - Antimicrobial peptides (AMPs) offer a potent and effective alternative for treatment of antibiotic resistant microbes. Mastoparans or...  相似文献   
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