Mycobacterial transcript cleavage factor Gre, exhibits chaperone-like activity

Publication date: Available online 22 May 2019Source: Biochimica et Biophysica Acta (BBA) - Proteins and ProteomicsAuthor(s): Abyson Joseph, Valakunja Nagaraja, Ramanathan NateshAbstractGre factors reactivate stalled elongation complexes by enhancing the intrinsic transcript cleavage activity of RNA polymerase. Previous work by us has shown that unlike in Escherichia coli (E.coli), Mycobacterium tuberculosis Gre factor is essential for its survival. Apart from their role in transcription regulation Gre factors have been implicated in stress response. A recent study has shown the role of E.coli GreA as a cellular chaperone, which inhibits aggregation of substrate proteins under heat stress condition. Moreover it was shown that GreA enables E.coli to survive heat shock and oxidative stress. In the current work, we have characterized the moonlighting chaperone activity and its plausible mechanism in Mycobacterium smegmatis Gre (MsGre) factor. We show here that MsGre prevents heat-induced aggregation of the substrate protein and also protects enzymatic activity. Interestingly Gre factor exists as a dimer in solution and does not undergo heat induced oligomerization. From the 8-anilino-1-naphthalene sulfonate (ANS) binding studies MsGre was shown to expose hydrophobic surface upon heat stress that would allow binding to unfolded or partially folded substrate protein. From Circular Dichroism (CD) studies, we also show that MsGre has a stable secondary structure under thermal stress...
Source: Biochimica et Biophysica Acta (BBA) Proteins and Proteomics - Category: Biochemistry Source Type: research

Related Links:

This article is protected by copyright. All rights reserved.
Source: FEBS Letters - Category: Biochemistry Authors: Tags: Review Source Type: research
;n MA Abstract The heat-inducible expression system has been widely used to produce recombinant proteins in Escherichia coli. However, the rise in temperature affects cell growth, activates the bacterial Heat-Shock Response (HSR), and promotes the formation of insoluble protein aggregates known as inclusion bodies (IBs). In this work, we evaluate the effect of the culture scale (shake flasks and bioreactors) and induction temperature (39 and 42 °C) on the kinetic behavior of thermoinducible recombinant E. coli ATCC 53606 producing rESAT-6 (6-kDa early-secretory antigenic target from Mycobacterium tubercul...
Source: Cell Stress and Chaperones - Category: Cytology Authors: Tags: Cell Stress Chaperones Source Type: research
Conclusion The marked metabolic differences in de novo lipogenesis and glycolysis in [18F]FDG and [18F]FAC uptakes in micro-PET imaging, respectively, help to differentiate chronic TB infection from acute infection.
Source: Nuclear Medicine Communications - Category: Nuclear Medicine Tags: ORIGINAL ARTICLES Source Type: research
In this study, rv0518 gene was cloned and expressed in E. coli followed by purification and characterization. It possessed lipolytic activity, preferably hydrolyzed pNP-decanoate at pH 9.0 and 40 °C. The enzyme was stable till 50 °C and wider pH range (5.0-11.0). The predicted active site residues, Ser-46, Asp-205, His-208, Gly-87, Asn-120 were confirmed by site directed mutagenesis. rv0518 gene expression in M. tuberculosis H37Ra was up-regulated under nutrient starvation and the protein was detected in membrane fraction. The expression of rv0518 in M. smegmatis altered the colony morphology/growth kinetics,...
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Tags: Int J Biol Macromol Source Type: research
Objectives: Identifying factors associated with mortality among acutely ill HIV-infected children presenting with advanced HIV disease may help clinicians optimize care for those at highest risk of death. Design: Using data from a randomized controlled trial (NCT02063880), we determined baseline sociodemographic, clinical, and laboratory cofactors of mortality among HIV-infected children in Kenya. Methods: We enrolled hospitalized, HIV-infected, antiretroviral therapy–naive children (0–12 years), initiated antiretroviral therapy, and followed up them for 6 months. We used Cox proportional hazards regres...
Source: JAIDS Journal of Acquired Immune Deficiency Syndromes - Category: Infectious Diseases Tags: Epidemiology Source Type: research
Publication date: Available online 3 May 2019Source: Microbial PathogenesisAuthor(s): Divakar Sharma, Manju Lata, Mohammad Faheem, Asad Ullah Khan, Beenu Joshi, Krishnamurthy Venkatesan, Sangeeta Shukla, Deepa BishtAbstractTuberculosis is an airborne infectious disease caused by Mycobacterium tuberculosis which threatens the globe. Aminoglycosides {Amikacin (AK) &Kanamycin (KM)} are WHO recommended second-line anti-TB drugs used against the treatment of drug-resistant tuberculosis. Aminoglycosides target the steps of protein translation machinery of M.tuberculosis. Several mechanisms have been put forward to elucidate ...
Source: Microbial Pathogenesis - Category: Infectious Diseases Source Type: research
Antonella Riccomi1, Giovanni Piccaro2, Dennis Christensen3, Carla Palma1, Peter Andersen3 and Silvia Vendetti1* 1Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy 2Notified Body, Istituto Superiore di Sanità, Rome, Italy 3Department of Infectious Diseases Immunology, Statens Serum Institute, Copenhagen, Denmark Most microbes invading through mucosal surfaces cause disease and therefore strategies to induce mucosal immune responses are strongly needed. Vitamin A metabolites, such as retinoic acid (RA), play crucial roles in programming T and B cells to home to mucosal compa...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Alessandro Poggi1*, Roberto Benelli2, Roberta Venè1, Delfina Costa1, Nicoletta Ferrari1, Francesca Tosetti1 and Maria Raffaella Zocchi3 1Molecular Oncology and Angiogenesis Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy 2Immunology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy 3Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy It is well established that natural killer (NK) cells are involved in both innate and adaptive immunity. Indeed, they can recognize molecules induced at the cell surface by stress signals ...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Gulcin Tezcan1, Ekaterina V. Martynova1, Zarema E. Gilazieva1, Alan McIntyre2, Albert A. Rizvanov1 and Svetlana F. Khaiboullina1,3* 1Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia 2Centre for Cancer Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom 3Department of Microbiology and Immunology, University of Nevada, Reno, Reno, NV, United States Inflammation has a crucial role in protection against various pathogens. The inflammasome is an intracellular multiprotein signaling complex that is linked to pathogen sensing and...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
In conclusion, the results improve our understanding on the characteristics of lncRNAs and mRNAs on regulating host immune response against C. perfringens type C infection, which will provide a reference for future research into exploring C. perfringens-related diseases in human. Introduction Clostridium perfringens (C. perfringens) is a Gram-positive anaerobic rod and ranks as the second most common bacteria that causes fulminant, fatal infectious and immune diseases (Scharff, 2012; Grass et al., 2013). These diseases are characterized by fever, pain, gas production, local edema, and severe tissue destruction, the...
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research
More News: Biochemistry | Gastroenteritis | Study | Tuberculosis