Sonika Bhatnagar

• Ph.D.
• Professor (Full) at Netaji Subhas University of Technology

Our previous report on Bacillus anthracis toxin-antitoxin module (MoxXT) identified it to be a two component system wherein, PemK-like toxin (MoxT) functions as a ribonuclease (Agarwal S et al. JBC 285:7254-7270, 2010). The labile antitoxin (MoxX) can bind to/neutralize the action of the toxin and is also a DNA-binding protein mediating autoregulat...

Backgound: Prokaryotic MazF family toxins co-occur with cognate antitoxins having divergent DNA binding folds and can be of chromosomal or plasmid origin. Sequence similarity search was carried out to identify the Toxin-Antitoxin (TA) operons of MazF family followed by sequence analysis and phylogenetic studies. The genomic DNA upstream of the TA o...

The prevalence of acquired hyperlipidemia has increased due to sedentary life style and lipid-rich diet. In this work, a lipid–protein–protein interaction network (LPPIN) for acquired hyperlipidemia was prepared by incorporating differentially expressed genes in obese fatty liver as seed nodes, protein interactions from PathwayLinker, and lipid int...

Large-scale visualization and analysis of HPIs involved in microbial CVDs can provide crucial insights into the mechanisms of pathogenicity. The comparison of CVD associated HPIs with the entire set of HPIs can identify the pathways specific to CVDs. Therefore, topological properties of HPI networks in CVDs and all pathogens was studied using Cytos...

Host‐pathogen interactions play a crucial role in invasion, infection, and induction of immune response in humans. In this work, four machine learning algorithms, namely Logistic regression, K‐nearest neighbor, Support Vector Machine, and Random Forest were implemented for the classification of drug targets. The algorithms were trained using 3400 h...

The spread of SARS-CoV-2 virus accompanied by public availability of abundant sequence data provides a window for the determination of viral evolutionary patterns. In this study, SARS-CoV-2 genome sequences were collected from seven countries in the period January 2020–December 2022. The sequences were classified into three phases, namely, pre-vacc...

DprE1 is involved in the synthesis of Mycobacterium tuberculosis cell wall and is a potent drug target for Tuberculosis (TB) treatment. The structure and dynamics of the loops L-I and L-II flanking the inhibitor binding site was studied using molecular dynamics (MD) simulation and MMPBSA in Amber v18. Docking and three-dimensional quantitative stru...

Mimicry of host proteins is a strategy employed by pathogens to hijack host functions. Domain and motif mimicry was explored in the experimental and predicted SARS-CoV-2-human interactome. The host first interactor proteins were also added to capture the continuum of the interactions. The domains and motifs of the proteins were annotated using NCBI...

The spread of SARS-CoV-2 virus accompanied by availability of abundant sequence data publicly, provides a window for determining the spatio-temporal patterns of viral evolution in response to vaccination. In this study, SARS-CoV-2 genome sequences were collected from seven countries in the period January 2020-December 2022. The sequences were class...

Background: Human neutrophil elastase (HNE) is a key driver of systemic and cardiopulmonary inflammation. Recent studies have established the existence of a pathologically active auto-processed form of HNE with reduced binding affinity against small molecule inhibitors. Method: AutoDock Vina v1.2.0 and Cresset Forge v10 software were used to dev...

Molecular mimicry of host proteins by pathogens constitutes a strategy to hijack the host pathways. At present, there is no dedicated resource for mimicked domains and motifs in the host–pathogen interactome. In this work, the experimental host–pathogen (HP) and host–host (HH) protein–protein interactions (PPIs) were collated. The domains and motif...

The host pathogen interactome can be visualized as a vast continuous network in which molecular mimicry of host proteins by pathogens constitutes a strategy to hijack the host pathways. Despite extensive work in this field, there is no dedicated resource for mimicked domains and motifs in host pathogen interactome. In this work, we collated all the...

https://doi.org/10.1016/j.compbiolchem.2021.107505

Hyperlipidemia causes diseases like cardiovascular disease, cancer, Type II Diabetes and Alzheimer’s disease. Drugs that specifically target HL associated diseases are required for treatment. 34 KEGG pathways targeted by lipid lowering drugs were used to construct a directed protein-protein interaction network and driver nodes were determined using...

Microbe induced cardiovascular diseases (CVDs) are less studied at present. Host-pathogen interactions (HPIs) between human proteins and microbial proteins associated with CVD can be found dispersed in existing molecular interaction databases. MorCVD database is a curated resource that combines 23,377 protein interactions between human host and 432...

The focal adhesion kinase-growth factor receptor 2 (FAK-Grb2) protein-protein interaction is implicated in pathogenesis of stress-induced cardiac hypertrophy. The focal adhesion targeting (FAT) domain of FAK unfolds to form a structural intermediate that interacts with a multibinding hot spot in the SH2 domain of Grb2. Disruption of the Grb2-FAT in...

Zinc has an abounding occurrence in the prokaryotes and plays paramount roles including catalytic, structural, and regulatory. Zinc uptake regulator (Zur), a Fur family transcriptional regulator, is connoted in maintaining zinc homeostasis in the pathogenic bacteria by binding to zinc and regulating the genes involved in zinc uptake and mobilizatio...

PH domains mediate interactions involved in cell signaling, intracellular membrane transport regulation and cytoskeleton organization. Some PH domains bind phosphoinositides with different affinity and specificity. The two novel PLCη (1 and 2) possess an N-terminal PH domain (PHη1 and PHη2 respectively) that has been implicated in membrane associat...

Focal adhesion kinase (FAK) is required for signaling in the heart. S910 phosphorylated FAK is known to cause pathological cardiac hypertrophy. The switching of FAK between its inactive (-i), activated (-a) and hyperactive (-h) state is controlled by phosphorylation. FAK consists of three domains, namely: FERM, Kinase, and FAT joined by linkers L1...

Hyperlipidemia (HL) is characterized by elevated level of plasma lipids affecting regular functioning of lipid-protein interactions leading to disease. The traditional lipid biomarkers utilized for detection of individuals with HL and Cardiovascular Diseases (CVD) risk, sometimes fail to predict future CVD events therefore, establishing need of nov...

The Focal adhesion kinase (FAT) domain of Focal Adhesion Kinase is a four helical bundle known for conformational plasticity. FAT adopts two distinctly different conformations i.e., close (cFAT) and arm-exchanged (aeFAT) states under native conditions [1]. The slow transition from cFAT to aeFAT is likely to proceed through an open intermediate stat...

The pleiotropism of the GTP-sensing transcriptional regulator CodY is evident by the gamut of processes that it regulates in almost all low G+C gram-positive bacteria, including general metabolism, biosynthesis of some amino acids and transport systems, nitrogen uptake, sporulation, biofilm formation, motility, and virulence. The role of CodY in vi...

Lipidomics is a new frontier of omics research and offers much promise for new-generation biomarkers for common complex phenotypes such as hyperlipidemia (HL) and cardiovascular diseases (CVDs). HL is a disorder characterized by increased levels of blood lipids and is a well-established risk factor for CVD. Traditional clinical markers for prognosi...

The key signaling pathways in cellular processes involve protein-protein interactions (PPIs). A perturbation in the balance of PPIs occurs in various pathophysiological processes. There are a large numbers of experimental methods for detection of PPIs. However, experimental PPI determination is time consuming, expensive, error prone and does not ef...

Sequence-structure deficit marks one of the critical problems in today's scenario where high-throughput sequencing has resulted in large datasets of protein sequences but their corresponding 3D structures still needs to be determined. Homology modeling, also termed as Comparative modeling refers to modeling of 3D structure of a protein by exploitin...

WalRK two-component system of Bacillus anthracis potentially regulates multiple genes spanning diverse cellular functions. Its constituent response regulator (RR), WalR belongs to the OmpR/PhoB family which possesses a winged helix-turn-helix motif for DNA binding. An in silico knowledge based model of WalR C-terminal DNA binding domain in complex...

Context: Thrombospondin1 (TSP1) participates in numerous signaling pathways critical for vascular physiology and disease. The conserved signature domain of thrombospondin 1 (TSP1-Sig1) comprises three epidermal growth factor (EGF), 13 calcium-binding type 3 thrombospondin (T3) repeats, and one lectin-like module arranged in a stalk-wire-globe topo...

The key signaling pathways in cellular processes involve protein-protein interactions (PPIs). A perturbation in the balance of PPIs occurs in various pathophysiological processes. There are a large numbers of experimental methods for detection of PPIs. However, experimental PPI determination is time consuming, expensive, error prone and does not ef...

The development of drug-resistant pathogenic bacteria poses challenges to global health for their treatment and control. In this context, stress response enables bacterial populations to survive extreme perturbations in the environment but remains poorly understood. Specific modules are activated for unique stressors with few recognized global regu...

Sequence-structure deficit marks one of the critical problems in today’s scenario where high-throughput sequencing has resulted in large datasets of protein sequences but their corresponding 3D structures still needs to be determined. Homology modeling, also termed as Comparative modeling refers to modeling of 3D structure of a protein by exploitin...

The focal adhesion targeting (FAT) domain of focal adhesion kinase (FAK) exists in monomeric closed (c) or arm exchanged (ae) dimeric state. FAT interaction with Grb2 necessitates an intermediate open (o) state that interacts with Grb2 and activates signaling pathways leading to pathological cardiac hypertrophy. Targeted molecular dynamics (TMD) si...

Vasoregression is a common phenomenon underlying physiological vessel development as well as pathological microvascular diseases leading to peripheral neuropathy, nephropathy, and vascular oculopathies. In this review, we describe the hallmarks and pathways of vasoregression. We argue here that there is a parallel between characteristic features of...

The Plasmodium falciparum telomerase reverse transcriptase (PfTERT) is a ribonucleoprotein that assists the maintenance of the telomeric ends of chromosomes by reverse transcription of its own RNA subunit. It represents an attractive therapeutic target for eradication of the plasmodial parasite at the asexual liver stage. Automated modeling using M...

Abstract Atherosclerosis is a life-threatening disease and a major cause of mortalities worldwide. While many of the atherosclerotic sequelae are reflected as microvascular effects in the eye, the molecular mechanisms of their development is not yet known. In this study, we employed a systems biology approach to unveil the most significant events a...

Bacillus anthracis MoxXT is a Type II proteic Toxin-Antitoxin (TA) module wherein MoxT is a ribonuclease that cleaves RNA specifically while MoxX interacts with MoxT and inhibits its activity. Disruption of the TA interaction has been proposed as a novel antibacterial strategy. Peptides, either based on antitoxin sequence or rationally designed, ha...

In soybean, a small hormone like peptide, leginsulin was found to bind Basic 7S Globulin (Bg7S) and stimulate its tyrosine kinase activity. The NMR-structure of leginsulin, along with crystal structure of Bg7S, was used to create a rigid docking model, followed by flexible refinement of the interaction complex. This study provides structural insigh...

Two-component signal transduction systems (TCS), consisting of a sensor histidine protein kinase and its cognate response regulator, are an important mode of environmental sensing in bacteria. Additionally, they have been found to regulate virulence determinants in several pathogens. Bacillus anthracis, the causative agent of anthrax and a bioterro...

In soybean, a small hormone like peptide, leginsulin was found to bind Basic 7S Globulin (Bg7S) and stimulate its tyrosine kinase activity. The NMR-structure of leginsulin, along with crystal structure of Bg7S, was used to create a rigid docking model, followed by flexible refinement of the interaction complex. This study provides structural insigh...

A microarray works by exploiting the ability of a given mRNA molecule to bind specifically to the DNA template from which it originated under specific high stringency conditions. After this, the amount of mRNA bound to each DNA site on the array is determined, which represents the expression level of each gene. Qualification of the mRNA (probe) bou...

Background: Dengue virus infection has recently taken endemic proportions in India with dengu type-3 (DEN-3) as a predominant serotype. In this study, we carried out the selection pressure analysis of three critical immunogenic regions of DEN-3. Phylogenetic analysis was then carried out on the positively selected genomic region in the DEN-3 virus...

Background: Dengue virus infection has recently taken endemic proportions in India with dengu type-3 (DEN-3) as a predominant serotype. In this study, we carried out the selection pressure analysis of three critical immunogenic regions of DEN-3. Phylogenetic analysis was then carried out on the positively selected genomic region in the DEN-3 virus...

BACKGROUND: In soybean, a protein called Basic 7S Globulin (Bg7S) is believed to be important for cell growth and differentiation control. Bg7S is present in middle lamella of the cell wall and a small hormone like peptide, leginsulin interacts with Bg7S to stimulate its tyrosine kinase activity. Crystal structure of Bg7S, released recently, was u...

The purinergic P2Y receptors are G-protein coupled receptors (GPCRs) that control many physiological processes by mediating cellular responses to purines, pyrimidines and their analogues. They can be used as potential therapeutic targets in a variety of disease conditions. Therefore, it is critical to identify new members of this family of receptor...

Bacillus anthracis genome harbors a toxin-antitoxin (TA) module encoding pemI (antitoxin) and pemK (toxin). This study describes the rPemK as a potent ribonuclease with a preference for pyrimidines (C/U), which is consistent with our previous study that demonstrated it as a translational attenuator. The in silico structural modeling of the PemK in...

Bacillus anthracis genome harbors a toxin-antitoxin (TA) module encoding pemI (antitoxin) and pemK (toxin). This study describes the rPemK as a potent ribonuclease with a preference for pyrimidines (C/U), which is consistent with our previous study that demonstrated it as a translational attenuator. The in silico structural modeling of the PemK in...

The purinergic P2Y receptors are critical determinants of physiological function playing diverse roles in cell proliferation, differentiation, and survival. However, in cancer cells they have been reported to assume contradictory roles at times, thus causing inhibition of proliferation, cell death, and apoptosis. A critical evaluation and analysis...

Insulin is a historic molecule. It presents many first instances, such as the first protein to be fully sequenced, one of the first proteins to be crystallized in pure form, one among the early proteins whose structure was investigated using X-ray crystallography, the first protein to be chemically synthesized and the first Biotech drug. Therefore,...

A crucial step in the replication of HIV-1 is the conversion of its single-stranded RNA to double-stranded DNA, which is catalyzed by the virally encoded reverse transcriptase (RT). The latter is therefore a key target for the development of anti-HIV drugs. Currently approved anti-RT drugs fall into two main classes: (i). nucleoside analog inhibito...

The insertion of viral DNA into the host chromosome is an essential step in the replication of HIV-1, and is carried out by an enzyme, HIV-1 integrase (IN). Since the latter has no human cellular counterpart, it is an attractive target for antiviral drug design. Several IN inhibitors having activities in the micromolar range have been reported to d...

ET-1 is the most potent vasoconstrictor known to date, causing vasoconstriction when bound to the ET(A) receptor. Inhibitors of the binding of ET-1 to the ET(A) receptor would be of immense value as potential therapeutic agents in the treatment of cardiovascular disorders such as angina and hypertension. We present here the rational design of such...

X-ray crystallography, NMR spectroscopy and theoretical studies on some oligopeptides containing dehydro-alanine (delta Ala) have indicated that delta Ala adopts an extended conformation and also induces a definite conformation in the preceding saturated residue. In order to evaluate the conformational constraints imposed by delta Ala on the neighb...