scholarly journals DNA binding ability mode, spectroscopic studies, hydrophobicity, and in vitro antibacterial evaluation of some new Fe(II) complexes bearing ONO donors amino acid Schiff bases

2017 ◽  
Vol 10 ◽  
pp. S1835-S1846 ◽  
Author(s):  
Laila H. Abdel-Rahman ◽  
Rafat M. El-Khatib ◽  
Lobna A.E. Nassr ◽  
Ahmed M. Abu-Dief
2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh ◽  
A. Mukherjee

The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR (1H,13C, and29Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated forin vitroantimicrobial activity against bacteria (Bacillus cereus,Nocardiaspp.,E. aerogenes,Escherichia coli,Klebsiellaspp., andStaphylococcusspp.). The complexes were found to be more potent as compared to the ligands.


2021 ◽  
Author(s):  
Chaofan Peng ◽  
Yuqian Tan ◽  
Peng Yang ◽  
Kangpeng Jin ◽  
Chuan Zhang ◽  
...  

Abstract BackgroundEmerging studies have investigated circRNAs as significant regulation factors in multiple cancer progression. Nevertheless, the biological functions and underlying mechanisms of circRNAs in colorectal cancer progression remain unclear.MethodsA novel circRNA (circ-GALNT16) was identified by microarray and qRT-PCR. A series of phenotype experiments in vitro and vivo were performed to investigate the role of circ-GALNT16 in CRC. FISH, RNA pulldown assay, RIP assay, RNA sequencing, coimmunoprecipitation, and ChIP were constructed to explore the molecular mechanisms of circ-GALNT16 in colorectal cancer.ResultsCirc-GALNT16 was downregulated in colorectal cancer and negatively correlated with poor prognosis. Circ-GALNT16 suppressed the proliferation and metastasis ability of colorectal cancer in vitro and vivo. Mechanistically, circ-GALNT16 could bind to the KH3 domain of heterogeneous nuclear ribonucleoprotein K (hnRNPK), which resulted in the SUMOylation of hnRNPK. Additionally, circ-GALNT16 could enhance the hnRNPK-p53 complex by facilitating the SUMOylation of hnRNPK. Furthermore, RNA sequencing assay identified serpin family E member 1 as the target gene of circ-GALNT16 at the transcriptional level. Rescue assays revealed that circ-GALNT16 regulated the expression of Serpine1 by inhibiting the deSUMOylation of hnRNPK mediated by SUMO specific peptidase 2 and then regulating the sequence-specific DNA binding ability of the hnRNPK-p53 transcriptional complex.ConclusionsCirc-GALNT16 suppressed CRC progression via inhibiting Serpine1 expression through adjusting the sequence-specific DNA binding ability of the SENP2-mediated hnRNPK-p53 transcriptional complex and might work as a biomarker and therapeutic target for CRC.


1992 ◽  
Vol 12 (5) ◽  
pp. 2372-2382
Author(s):  
K M Arndt ◽  
S L Ricupero ◽  
D M Eisenmann ◽  
F Winston

A mutation in the gene that encodes Saccharomyces cerevisiae TFIID (SPT15), which was isolated in a selection for mutations that alter transcription in vivo, changes a single amino acid in a highly conserved region of the second direct repeat in TFIID. Among eight independent spt15 mutations, seven cause this same amino acid change, Leu-205 to Phe. The mutant TFIID protein (L205F) binds with greater affinity than that of wild-type TFIID to at least two nonconsensus TATA sites in vitro, showing that the mutant protein has altered DNA binding specificity. Site-directed mutations that change Leu-205 to five different amino acids cause five different phenotypes, demonstrating the importance of this amino acid in vivo. Virtually identical phenotypes were observed when the same amino acid changes were made at the analogous position, Leu-114, in the first repeat of TFIID. Analysis of these mutations and additional mutations in the most conserved regions of the repeats, in conjunction with our DNA binding results, suggests that these regions of the repeats play equivalent roles in TFIID function, possibly in TATA box recognition.


2003 ◽  
Vol 23 (15) ◽  
pp. 5208-5216 ◽  
Author(s):  
Jeong-Ho Kim ◽  
Jeffrey Polish ◽  
Mark Johnston

ABSTRACT Rgt1 is a glucose-responsive transcription factor that binds to the promoters of several HXT genes encoding glucose transporters in Saccharomyces cerevisiae and regulates their expression in response to glucose. Rgt1 contains a Zn2Cys6 binuclear cluster responsible for DNA binding. Most proteins that contain this sequence motif bind as dimers to regularly spaced pairs of the sequence CGG. However, there are no CGG pairs with regular spacing in promoters of genes regulated by Rgt1, suggesting that Rgt1 binds as a monomer to CGG or to another sequence. We identified the Rgt1 consensus binding site sequence 5′-CGGANNA-3′, multiple copies of which are present in all HXT promoters regulated by Rgt1. Rgt1 binds in vivo to multiple sites in the HXT3 promoter in a nonadditive, synergistic manner, leading to synergistic repression of HXT3 transcription. We show that glucose inhibits the DNA-binding ability of Rgt1, thereby relieving repression of HXT gene expression. This regulation of Rgt1 DNA-binding activity is caused by its glucose-induced phosphorylation: the hyperphosphorylated Rgt1 present in cells growing on high levels of glucose does not bind DNA in vivo or in vitro; dephosphorylation of this form of Rgt1 in vitro restores its DNA-binding ability. Furthermore, an altered Rgt1 that functions as a constitutive repressor remains hypophosphorylated when glucose is added to cells and binds DNA under these conditions. These results suggest that glucose regulates the DNA-binding ability of Rgt1 by inducing its phosphorylation.


1991 ◽  
Vol 11 (2) ◽  
pp. 928-934 ◽  
Author(s):  
D J Ebbole ◽  
J L Paluh ◽  
M Plamann ◽  
M S Sachs ◽  
C Yanofsky

CPCI, the principal regulatory protein required for cross-pathway control of amino acid biosynthetic genes in Neurospora crassa, contains a domain similar to the DNA-binding domain of GCN4, the corresponding general regulator in Saccharomyces cerevisiae. We examined binding by CPC1 synthesized in vitro and by CPC1 present in N. crassa whole-cell extracts. CPCI from both sources was shown to bind to the DNA sequence 5'-ATGACTCAT-3', which is also the preferred recognition sequence of GCN4, CPC1 was confirmed as the source of DNA-binding activity in extracts by immunoblotting. Slightly mobility differences between DNA complexes containing CPCI synthesized in vitro and CPC1 in mycelial extracts were observed. Analyses of N. crassa extracts from different stages of asexual development revealed that CPC1 was abundant immediately following spore germination and through early mycelial growth but was scarce subsequently. CPC1 levels could be increased at any time by imposing amino acid starvation. Copies of the CPC1 response element are located upstream of several genes regulated by cross-pathway control, including cpc-1 itself.


2017 ◽  
Vol 10 (3) ◽  
pp. 06-14
Author(s):  
Mohammad Ibrahim ◽  
Asif Khan ◽  
Bushra Faiz ◽  
Muhammad Ikram ◽  
HazratUn Nabi ◽  
...  

2017 ◽  
Author(s):  
Michael W. Dorrity ◽  
Josh T. Cuperus ◽  
Jolie A. Carlisle ◽  
Stanley Fields ◽  
Christine Queitsch

AbstractIn Saccharomyces cerevisiae, the decision to mate or invade relies on environmental cues that converge on a shared transcription factor, Ste12. Specificity toward invasion occurs via Ste12 binding cooperatively with the co-factor Tec1. Here, we characterize the in vitro binding preferences of Ste12 to identify a defined spacing and orientation of dimeric sites, one that is common in pheromone-regulated genes. We find that single amino acid changes in the DNA-binding domain of Ste12 can shift the preference of yeast toward either mating or invasion. These mutations define two distinct regions of this domain, suggesting alternative modes of DNA binding for each trait. Some exceptional Ste12 mutants promote hyperinvasion in a Tec1-independent manner; these fail to bind cooperative sites with Tec1 and bind to unusual dimeric Ste12 sites that contain one highly degenerate half site. We propose a model for how activation of invasion genes could have evolved with Ste12 alone.


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