scholarly journals CMPyMOL: An Interactive PyMOL extension for Protein Contact-Map Analysis

2016 ◽  
Author(s):  
Venkatramanan Krishnamani
Keyword(s):  
Protein Interactions ◽  
Spatial Organization ◽  
Spatial Configuration ◽  
3D Visualization ◽  
Structural Features ◽  
Biochemical Properties ◽  
Contact Map ◽  
Reduced Representation ◽  
Contact Maps ◽  
Graphical Tool

AbstractContact–maps are reduced 2D representation of the 3D spatial configuration of a protein. Many valuable structural features like secondary structures, inter- and intra-protein interactions,interacting domains, etc., can be readily identified from these maps. However, it is not straightforward and intuitive to reckon the spatial organization of the contact regions from reduced representation. The CMPyMOL extention for molecular visualization software PyMOL attempts to bridge this gap as an interactive graphical tool for protein contact-maps that interfaces with PyMOL for 3D visualization. Specifically, CMPyMOL helps understand the functional importance of contacts by providing visual overlays of various structural and biochemical properties of a protein on top of its contact-map.

scholarly journals ConPlot: web-based application for the visualization of protein contact maps integrated with other data

2021 ◽  
Author(s):  
Filomeno Sánchez Rodríguez ◽  
Shahram Mesdaghi ◽  
Adam J Simpkin ◽  
J Javier Burgos-Mármol ◽  
David L Murphy ◽  
...  
Keyword(s):  
Empty Space ◽  
Structural Features ◽  
Supplementary Information ◽  
Contact Map ◽  
Web Based ◽  
Contact Maps ◽  
File Formats ◽  
Residue Contacts ◽  
Contact Data ◽  
Protein Contact Maps

Abstract Summary Covariance-based predictions of residue contacts and inter-residue distances are an increasingly popular data type in protein bioinformatics. Here we present ConPlot, a web-based application for convenient display and analysis of contact maps and distograms. Integration of predicted contact data with other predictions is often required to facilitate inference of structural features. ConPlot can therefore use the empty space near the contact map diagonal to display multiple coloured tracks representing other sequence-based predictions. Popular file formats are natively read and bespoke data can also be flexibly displayed. This novel visualization will enable easier interpretation of predicted contact maps. Availability and implementation available online at www.conplot.org, along with documentation and examples. Alternatively, ConPlot can be installed and used locally using the docker image from the project’s Docker Hub repository. ConPlot is licensed under the BSD 3-Clause. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals Identification and Utilization of Copy Number Information for Correcting Hi-C Contact Map of Cancer Cell Line

2019 ◽  
Author(s):  
Ahmed Ibrahim Samir Khalil ◽  
Siti Rawaidah Mohammad Muzaki ◽  
Anupam Chattopadhyay ◽  
Amartya Sanyal
Keyword(s):  
Cell Line ◽  
Copy Number ◽  
Spatial Organization ◽  
Cancer Cell Line ◽  
Copy Number Variations ◽  
Interaction Matrix ◽  
Contact Map ◽  
Contact Maps ◽  
Systematic Biases ◽  
The Impact

AbstractMotivationHi-C and its variant techniques have been developed to capture the spatial organization of chromatin. Normalization of Hi-C contact maps is essential for accurate modeling and interpretation of genome-wide chromatin conformation. Most Hi-C correction methods are originally developed for normal cell lines and mainly target systematic biases. In contrast, cancer genomes carry multi-level copy number variations (CNVs). Copy number influences interaction frequency between genomic loci. Therefore, CNV-driven bias needs to be corrected for generating euploid-equivalent chromatin contact maps.ResultsWe developed HiCNAtra framework that extracts read depth (RD) signal from Hi-C or 3C-seq reads to generate the high-resolution CNV profile and use this information to correct the contact map. We proposed the “entire restriction fragment” counting for better estimation of the RD signal and generation of CNV profiles. HiCNAtra integrates CNV information along with other systematic biases for explicitly correcting the interaction matrix using Poisson regression model. We demonstrated that RD estimation of HiCNAtra recapitulates the whole-genome sequencing (WGS)-derived coverage signal of the same cell line. Benchmarking against OneD method (only explicit method to target CNV bias) showed that HiCNAtra fared better in eliminating the impact of CNV on the contact maps.Availability and implementationHiCNAtra is an open source software implemented in MATLAB and is available at https://github.com/AISKhalil/HiCNAtra.

Protein Interaction Domains and Post-Translational Modifications: Structural Features and Drug Discovery Applications

2020 ◽  
Vol 27 (37) ◽  
pp. 6306-6355 ◽  
Author(s):  
Marian Vincenzi ◽  
Flavia Anna Mercurio ◽  
Marilisa Leone
Keyword(s):  
Drug Discovery ◽  
Protein Interaction ◽  
Protein Interactions ◽  
Structural Information ◽  
Protein Complexes ◽  
Structural Features ◽  
Protein Protein Interactions ◽  
Modular Architecture ◽  
Post Translational Modifications ◽  
Interaction Domains

Background:: Many pathways regarding healthy cells and/or linked to diseases onset and progression depend on large assemblies including multi-protein complexes. Protein-protein interactions may occur through a vast array of modules known as protein interaction domains (PIDs). Objective:: This review concerns with PIDs recognizing post-translationally modified peptide sequences and intends to provide the scientific community with state of art knowledge on their 3D structures, binding topologies and potential applications in the drug discovery field. Method:: Several databases, such as the Pfam (Protein family), the SMART (Simple Modular Architecture Research Tool) and the PDB (Protein Data Bank), were searched to look for different domain families and gain structural information on protein complexes in which particular PIDs are involved. Recent literature on PIDs and related drug discovery campaigns was retrieved through Pubmed and analyzed. Results and Conclusion:: PIDs are rather versatile as concerning their binding preferences. Many of them recognize specifically only determined amino acid stretches with post-translational modifications, a few others are able to interact with several post-translationally modified sequences or with unmodified ones. Many PIDs can be linked to different diseases including cancer. The tremendous amount of available structural data led to the structure-based design of several molecules targeting protein-protein interactions mediated by PIDs, including peptides, peptidomimetics and small compounds. More studies are needed to fully role out, among different families, PIDs that can be considered reliable therapeutic targets, however, attacking PIDs rather than catalytic domains of a particular protein may represent a route to obtain selective inhibitors.

Spatial organization enhances versatility and specificity in cyclic di-GMP signaling

2020 ◽  
Vol 401 (12) ◽  
pp. 1323-1334
Author(s):  
Sandra Kunz ◽  
Peter L. Graumann
Keyword(s):  
Protein Interactions ◽  
Cell Cycle Progression ◽  
Spatial Organization ◽  
Caulobacter Crescentus ◽  
Second Messenger ◽  
Protein Protein Interactions ◽  
Spatial Cues ◽  
Signaling Specificity ◽  
Regulatory Circuits ◽  
Second Messenger Signaling

AbstractThe second messenger cyclic di-GMP regulates a variety of processes in bacteria, many of which are centered around the decision whether to adopt a sessile or a motile life style. Regulatory circuits include pathogenicity, biofilm formation, and motility in a wide variety of bacteria, and play a key role in cell cycle progression in Caulobacter crescentus. Interestingly, multiple, seemingly independent c-di-GMP pathways have been found in several species, where deletions of individual c-di-GMP synthetases (DGCs) or hydrolases (PDEs) have resulted in distinct phenotypes that would not be expected based on a freely diffusible second messenger. Several recent studies have shown that individual signaling nodes exist, and additionally, that protein/protein interactions between DGCs, PDEs and c-di-GMP receptors play an important role in signaling specificity. Additionally, subcellular clustering has been shown to be employed by bacteria to likely generate local signaling of second messenger, and/or to increase signaling specificity. This review highlights recent findings that reveal how bacteria employ spatial cues to increase the versatility of second messenger signaling.

scholarly journals Protein–Protein Interactions in Translesion Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5544
Author(s):  
Radha Charan Dash ◽  
Kyle Hadden
Keyword(s):  
Protein Interactions ◽  
Acquired Resistance ◽  
Translesion Synthesis ◽  
Initial Response ◽  
Structural Features ◽  
Dna Lesions ◽  
Protein Protein Interactions ◽  
Dna Damage Tolerance ◽  
Response To Chemotherapy ◽  
Depth Analysis

Translesion synthesis (TLS) is an error-prone DNA damage tolerance mechanism used by actively replicating cells to copy past DNA lesions and extend the primer strand. TLS ensures that cells continue replication in the presence of damaged DNA bases, albeit at the expense of an increased mutation rate. Recent studies have demonstrated a clear role for TLS in rescuing cancer cells treated with first-line genotoxic agents by allowing them to replicate and survive in the presence of chemotherapy-induced DNA lesions. The importance of TLS in both the initial response to chemotherapy and the long-term development of acquired resistance has allowed it to emerge as an interesting target for small molecule drug discovery. Proper TLS function is a complicated process involving a heteroprotein complex that mediates multiple attachment and switching steps through several protein–protein interactions (PPIs). In this review, we briefly describe the importance of TLS in cancer and provide an in-depth analysis of key TLS PPIs, focusing on key structural features at the PPI interface while also exploring the potential druggability of each key PPI.

scholarly journals Molecular mechanisms associated with clustered lesion-induced impairment of 8-oxoG recognition by the human glycosylase OGG1

2021 ◽  
Author(s):  
Tao Jiang ◽  
Antonio MONARI ◽  
Elise Dumont ◽  
Emmanuelle Bignon
Keyword(s):  
Protein Interactions ◽  
Molecular Mechanisms ◽  
Excision Repair ◽  
Structural Features ◽  
Repair Pathway ◽  
Dna Lesion ◽  
Damage Response ◽  
Base Excision ◽  
Structural Signature ◽  
Dynamics Simulations

The 8-oxo-7,8-dihydroguanine, referred to as 8-oxoG, is a highly mutagenic DNA lesion that can provoke the appearance of mismatches if it escapes the DNA Damage Response. The specific recognition of its structural signature by the hOGG1 glycosylase is the first step along the Base Excision Repair pathway, that ensures the integrity of the genome by preventing the emergence of mutations. 8-oxoG formation, structural features and repair have been the matter of extensive research and more recently this active field of research expended to the more complicated case of 8-oxoG within clustered lesions. Indeed, the presence of a second lesion within 1 or 2 helix turns can dramatically impact the repair yields of 8-oxoG by glycosylases. In this work, we use mu-range molecular dynamics simulations and machine learning-based post-analysis to explore the molecular mechanisms associated with the recognition of 8-oxoG by hOGG1 when embedded in a multiple lesions site with a mismatch in 5' or 3'. We delineate the stiffening of the DNA-protein interactions upon the presence of the mismatches, and rationalize the much lower repair yields reported with a 5' mismatch by describing the perturbation of 8-oxoG structural features upon addition of an adjacent lesion.

In silico specificity determination of neoantigen-reactive T-lymphocytes

2021 ◽  
Vol 67 (3) ◽  
pp. 251-258
Author(s):  
A.E. Kniga ◽  
I.V. Polyakov ◽  
A.V. Nemukhin
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Molecular Docking ◽  
Protein Interactions ◽  
Structural Features ◽  
Immune Recognition ◽  
Protein Protein Interactions ◽  
Binary Classifiers

Effective personalized immunotherapies of the future will need to capture not only the peculiarities of the patient’s tumor but also of his immune response to it. In this study, using results of in vitro high-throughput specificity assays, and combining comparative models of pMHCs and TCRs using molecular docking, we have constructed all-atom models for the putative complexes of all their possible pairwise TCR-pMHC combinations. For the models obtained we have calculated a dataset of physics-based scores and have trained binary classifiers that perform better compared to their solely sequence-based counterparts. These structure-based classifiers pinpoint the most prominent energetic terms and structural features characterizing the type of protein-protein interactions that underlies the immune recognition of tumors by T cells.

Quantitative polymorphism of tandem repeats as a method of epigenetic regulation of the of human cells response to oxidative stress

2020 ◽  
pp. 68-70
Author(s):  
Н.Н. Вейко ◽  
Е.С. Ершова ◽  
М.С. Конькова ◽  
Е.М. Малиновская ◽  
С.В. Костюк
Keyword(s):  
Adaptive Response ◽  
Spatial Organization ◽  
Tandem Repeats ◽  
Spatial Configuration ◽  
Human Cells ◽  
Central Regions ◽  
Schizophrenic Patients ◽  
Response To Stress ◽  
Cell Genome ◽  
And Function

Пространственная организация хроматина важна для нормального функционирования клетки. На архитектуру ядра влияют размеры отдельных фрагментов генома, которые коррелируют с числом копий этих фрагментов. Перемещение локусов 1q12 от поверхности ядра в центральные области является ключевой стадией адаптивного ответа клетки на стресс. Мы предположили, что размер локусов 1q12, который коррелирует с содержанием повтора f-SatIII, может влиять на перемещение этих участков хроматина в ядре. Методом FISH на выделенных лимфоцитах показали, что в контроле локусы 1q12 расположены вблизи поверхности ядра, в ядрах лимфоцитов больных шизофренией (БШ) и облученных контрольных клеток локусы 1q12 расположены в центральных районах ядра. Длительное культивирование облученных лимфоцитов сопровождалось гибелью клеток, и снижением содержания f-SatIII в ДНК. Очевидно, что погибали клетки с большим размером 1q12 (много f-SatIII), обогащая популяцию клетками с низким содержанием f-SatIII. В клетках БШ и в облученных клетках мы обнаружили повышение уровня РНК SATIII. Размеры гетерохроматина 1q12 в клетках человека могут влиять на процессы пролиферации и ответа клетки на стресс. Количественный полиморфизм тандемных повторов генома - один из эпигенетических механизмов регуляции ответа клеток на окислительный стресс. The spatial organization of chromatin is important for the normal functioning of the cell. Genome repeat cluster sizes can affect the chromatin spatial configuration and function. The 1q12 heterochromatin loci movement from the periphery to the center of the nucleus is the cells’ universal response to various types of stress. We hypothesized that a large 1q12 domain could affect chromatin movement, thereby inhibiting adaptive response (AR). Using the FISH method, we shown that in the control, 1q12 loci are located near the surface of the nucleus; in the lymphocyte nuclei of schizophrenic patients and irradiated control cells, 1q12 loci are located in the central regions of the nucleus. During prolonged cultivation, the irradiated cells with a large Large f-SatIII amount die and the population is enriched with the cells with low f-SatIII content. In intact SZ patients’ lymphocytes and in irradiated cells we found an increase in SATIII RNA levels. The size of heterochromatin 1q12 loci in human cells can affect to the proliferation and cells’ adaptive response to stress. Quantitative polymorphism of tandem genome repeats is one of the epigenetic mechanisms of genome expression’s regulation.

scholarly journals Proanthocyanidins: Oligomeric Structures with Unique Biochemical Properties and Great Therapeutic Promise

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Zhanjie Xu ◽  
Peng Du ◽  
Peter Meiser ◽  
Claus Jacob
Keyword(s):  
Protein Interactions ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Chemical Properties ◽  
Cancer Chemoprevention ◽  
Biochemical Properties ◽  
Synthetic Methods ◽  
Practical Applications ◽  
Wide Range ◽  
Physical And Chemical

Proanthocyanidins represent a unique class of oligomeric and polymeric secondary metabolites found ubiquitously and in considerable amounts in plants and some algae. These substances exhibit a range of rather surprising physical and chemical properties which, once applied to living organisms, are translated into a multitude of biological activities. The latter include antioxidant properties, cancer chemoprevention, anti-inflammatory and anti-diabetic effects as well as some exceptional, yet highly interesting activities, such as anti-nutritional and antimicrobial activity. Despite the wide range of activities and possible medical/agricultural applications of proanthocyanidins, many questions still remain, including issues related to bioavailability, metabolism and the precise biochemical, extra- and intracellular targets and mode(s) of action of these highly potent materials. Among the various physical and chemical interactions of such substances, strong binding to proteins appears to form the basis of many of their biological activities. Once easy-to-use synthetic methods to produce appropriate quantities of pure proanthocyanidins are available, it will be possible to identify the prime biological targets of these oligomers, study oligomer-protein interactions in more detail and develop possible practical applications in medicine and agriculture.

scholarly journals Conserved Central Intraviral Protein Interactome of the Herpesviridae Family

mSystems ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Anna Hernández Durán ◽  
Kay Grünewald ◽  
Maya Topf
Keyword(s):  
Protein Interactions ◽  
Computational Models ◽  
Functional Organization ◽  
Driving Forces ◽  
Protein Complexes ◽  
Structural Features ◽  
System Level ◽  
Protein Protein Interactions ◽  
Protein Interactome ◽  
Essential Components

ABSTRACT Protein interactions are major driving forces behind the functional phenotypes of biological processes. As such, evolutionary footprints are reflected in system-level collections of protein-protein interactions (PPIs), i.e., protein interactomes. We conducted a comparative analysis of intraviral protein interactomes for representative species of each of the three subfamilies of herpesviruses (herpes simplex virus 1, human cytomegalovirus, and Epstein-Barr virus), which are highly prevalent etiologic agents of important human diseases. The intraviral interactomes were reconstructed by combining experimentally supported and computationally predicted protein-protein interactions. Using cross-species network comparison, we then identified family-wise conserved interactions and protein complexes, which we defined as a herpesviral “central” intraviral protein interactome. A large number of widely accepted conserved herpesviral protein complexes are present in this central intraviral interactome, encouragingly supporting the biological coherence of our results. Importantly, these protein complexes represent most, if not all, of the essential steps required during a productive life cycle. Hence the central intraviral protein interactome could plausibly represent a minimal infectious interactome of the herpesvirus family across a variety of hosts. Our data, which have been integrated into our herpesvirus interactomics database, HVint2.0, could assist in creating comprehensive system-level computational models of this viral lineage. IMPORTANCE Herpesviruses are an important socioeconomic burden for both humans and livestock. Throughout their long evolutionary history, individual herpesvirus species have developed remarkable host specificity, while collectively the Herpesviridae family has evolved to infect a large variety of eukaryotic hosts. The development of approaches to fight herpesvirus infections has been hampered by the complexity of herpesviruses’ genomes, proteomes, and structural features. The data and insights generated by our study add to the understanding of the functional organization of herpesvirus-encoded proteins, specifically of family-wise conserved features defining essential components required for a productive infectious cycle across different hosts, which can contribute toward the conceptualization of antiherpetic infection strategies with an effect on a broader range of target species. All of the generated data have been made freely available through our HVint2.0 database, a dedicated resource of curated herpesvirus interactomics purposely created to promote and assist future studies in the field.

Sign in / Sign up

Export Citation Format

Share Document