Study of DNA-Binding Activity and Antibacterial Effect of Escitalopram Oxalate, an Extensively Prescribed Antidepressant

Drug Research ◽  
2019 ◽  
Vol 69 (10) ◽  
pp. 545-550
Author(s):  
Reza Valipour ◽  
Mehmet Bertan Yilmaz ◽  
Ebrahim Valipour
Keyword(s):  
Bacillus Subtilis ◽  
Free Radical ◽  
Dna Binding ◽  
Bacterial Growth ◽  
Antibacterial Effect ◽  
Antidepressant Drug ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Hydroxyl Free Radical ◽  
Drug Solution

AbstractEscitalopram oxalate (EO) is considered as one of the extensively prescribed antidepressant drug in Turkey and some other countries, therefore this research was aimed to study the interaction of the drug with DNA and study of the substance effect on bacterial growth. The absorption value of the drug solution at 238 nm was increased when DNA was added gradually to it and it showed hyperchromism effect. The value obtained for DNA binding constant (Kb) was 0.035 M −1. When we added the CuCl2 2H2O to the mixture, any breakage was not shown in double strand DNA in comparison with control DNA. In addition low concentration of EO couldn’t protect DNA (0.5273 µmole bp) against Hydroxyl free radical (0.12 µmole) although it could protect the DNA when it was at the same or higher concentrations (0.5273, 5.273 and 252.73 µmole) than the DNA concentration. In addition, MIC of the drug for E.coli and Bacillus subtilis was almost 0.185 mM and 0.55 mM respectively. The E.coli strain was killed at concentrations 45, 15, 5 mM while the Bacillus subtilis was stable against all of the concentrations.

scholarly journals Specificity of DNA binding activity of the Bacillus subtilis catabolite control protein CcpA.

1995 ◽  
Vol 177 (17) ◽  
pp. 5129-5134 ◽  
Author(s):  
J H Kim ◽  
Z T Guvener ◽  
J Y Cho ◽  
K C Chung ◽  
G H Chambliss
Keyword(s):  
Bacillus Subtilis ◽  
Dna Binding ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Control Protein ◽  
Catabolite Control

scholarly journals Interaction of Bacillus subtilis Fur (Ferric Uptake Repressor) with the dhb Operator In Vitro and In Vivo

1999 ◽  
Vol 181 (14) ◽  
pp. 4299-4307 ◽  
Author(s):  
Nada Bsat ◽  
John D. Helmann
Keyword(s):  
Bacillus Subtilis ◽  
Dna Binding ◽  
Rna Polymerase ◽  
Metal Ion ◽  
Regulatory Region ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Metalloregulatory Proteins

ABSTRACT Bacillus subtilis contains three metalloregulatory proteins belonging to the ferric uptake repressor (Fur) family: Fur, Zur, and PerR. We have overproduced and purified Fur protein and analyzed its interaction with the operator region controlling the expression of the dihydroxybenzoate siderophore biosynthesis (dhb) operon. The purified protein binds with high affinity and selectivity to the dhb regulatory region. DNA binding does not require added iron, nor is binding reduced by dialysis of Fur against EDTA or treatment with Chelex. Fur selectively inhibits transcription from the dhb promoter by ςA RNA polymerase, even if Fur is added after RNA polymerase holoenzyme. Since neither DNA binding nor inhibition of transcription requires the addition of ferrous ion in vitro, the mechanism by which iron regulates Fur function in vivo is not obvious. Mutagenesis of the furgene reveals that in vivo repression of the dhb operon by iron requires His97, a residue thought to be involved in iron sensing in other Fur homologs. Moreover, we identify His96 as a second likely iron ligand, since a His96Ala mutant mediates repression at 50 μM but not at 5 μM iron. Our data lead us to suggest that Fur is able to bind DNA independently of bound iron and that the in vivo role of iron is to counteract the effect of an inhibitory factor, perhaps another metal ion, that antagonizes this DNA-binding activity.

scholarly journals Structure of the p53/RNA polymerase II assembly

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shu-Hao Liou ◽  
Sameer K. Singh ◽  
Robert H. Singer ◽  
Robert A. Coleman ◽  
Wei-Li Liu
Keyword(s):  
Dna Binding ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Conformational Changes ◽  
P53 Protein ◽  
Binding Activity ◽  
Transactivation Domain ◽  
Pol Ii ◽  
Dna Binding Activity ◽  
Regulated Gene Expression

AbstractThe tumor suppressor p53 protein activates expression of a vast gene network in response to stress stimuli for cellular integrity. The molecular mechanism underlying how p53 targets RNA polymerase II (Pol II) to regulate transcription remains unclear. To elucidate the p53/Pol II interaction, we have determined a 4.6 Å resolution structure of the human p53/Pol II assembly via single particle cryo-electron microscopy. Our structure reveals that p53’s DNA binding domain targets the upstream DNA binding site within Pol II. This association introduces conformational changes of the Pol II clamp into a further-closed state. A cavity was identified between p53 and Pol II that could possibly host DNA. The transactivation domain of p53 binds the surface of Pol II’s jaw that contacts downstream DNA. These findings suggest that p53’s functional domains directly regulate DNA binding activity of Pol II to mediate transcription, thereby providing insights into p53-regulated gene expression.

scholarly journals Abundance Changes of the Response Regulator RcaC Require Specific Aspartate and Histidine Residues and Are Necessary for Normal Light Color Responsiveness

2008 ◽  
Vol 190 (21) ◽  
pp. 7241-7250 ◽  
Author(s):  
Lina Li ◽  
David M. Kehoe
Keyword(s):  
Dna Binding ◽  
Dynamic Range ◽  
Response Regulator ◽  
Red Light ◽  
Green Light ◽  
Binding Activity ◽  
Transcriptional Responses ◽  
Dna Binding Activity ◽  
Normal Light ◽  
Light Color

ABSTRACT RcaC is a large, complex response regulator that controls transcriptional responses to changes in ambient light color in the cyanobacterium Fremyella diplosiphon. The regulation of RcaC activity has been shown previously to require aspartate 51 and histidine 316, which appear to be phosphorylation sites that control the DNA binding activity of RcaC. All available data suggest that during growth in red light, RcaC is phosphorylated and has relatively high DNA binding activity, while during growth in green light RcaC is not phosphorylated and has less DNA binding activity. RcaC has also been found to be approximately sixfold more abundant in red light than in green light. Here we demonstrate that the light-controlled abundance changes of RcaC are necessary, but not sufficient, to direct normal light color responses. RcaC abundance changes are regulated at both the RNA and protein levels. The RcaC protein is significantly less stable in green light than in red light, suggesting that the abundance of this response regulator is controlled at least in part by light color-dependent proteolysis. We provide evidence that the regulation of RcaC abundance does not depend on any RcaC-controlled process but rather depends on the presence of the aspartate 51 and histidine 316 residues that have previously been shown to control the activity of this protein. We propose that the combination of RcaC abundance changes and modification of RcaC by phosphorylation may be necessary to provide the dynamic range required for transcriptional control of RcaC-regulated genes.

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