Biophysical analysis of MarR family transcription factors from Streptomyces coelicolor

Streptomycetes represent a rich source of potentially useful therapeutics. However, in a laboratory environment, a large proportion of their secondary metabolite gene clusters remain silent, and thus their full metabolic potential is not realised. One way to unlock these so-called "cryptic" clusters may be to manipulate specific regulatory proteins. But, the vast majority of these regulators are uncharacterized, making it difficult to do this in a rational way. The MarR family of regulatory proteins (MFRs) represents an important group of transcriptional regulators. Named after the first to be characterized in Escherichia coli, the multiple antibiotic resistance repressor (MarR), the members of this family are involved in a number of biological processes which include antibiotic resistance, virulence, oxidative stress responses and pathogenesis and are therefore of significant clinical interest. There are 42 of these MFRs present in the genome of Streptomyces coelicolor, a prolific producer of secondary metabolites, the majority of which are uncharacterized. In this work, the crystal structures of three of these MFRs from Streptomyces coelicolor, Sco3914, Sco4122 and Sco5413, have been determined using anomalous dispersion methods. The structure of Sco5413 was determined to 1.25 Å resolution, the highest resolution for an MFR at this point. Genetic and biophysical analyses of these transcription factors have also been performed and the DNA footprints of Sco3914 and Sco4122 have been defined. Disruption mutants for each of the genes have been created and phenotypic analysis revealed a distinct phenotype for Sco5413. The structures do not reveal a ligand for any of the structures, but comparisons with other MFR structures provide some evidence towards a conserved ligand binding site amongst MFRs

Accelerating progress in the Replacement, Reduction and Refinement of animal testing through better knowledge sharing

In the context of the European Commission's Communication published in response to the European Citizens' Initiative "Stop Vivisection", Action 1 aimed to conduct an assessment of current technologies, information sources and networks from all relevant sectors with potential impact on the advancement of the refinement, reduction and replacement of animals used for scientific purposes (the "Three Rs"). The main objective of this study is to map knowledge sources relevant to the Three Rs, to examine how knowledge is being shared, and to identify possible gaps and opportunities to enhance knowledge sharing. An inventory of knowledge sources (KS) potentially relevant to the Three Rs used in the area of life sciences has been compiled which should be viewed as a snapshot of the current status of knowledge sources available (the supply), and as a starting point for further analysis of knowledge sharing strategies. A public survey was also conducted to complement this study (supply versus demand), and to inform on how to proceed effectively with any knowledge management strategy. The survey has revealed that many involved in this area consider that whilst access to relevant knowledge sources is adequate, there is a need for better coordination of the sources, as well as for the communication of information. Opportunities for face-to-face exchanges are highly valued and there is a firm call for more developments in education and training at professional, university and secondary school levels.JRC.F.3-Chemicals Safety and Alternative Method

NASA Applied Sciences' DEVELOP Program Fosters the Next Generation of Earth Remote Sensing Scientists

Satellite remote sensing technology and the science associated with the evaluation of the resulting data are constantly evolving. To meet the growing needs related to this industry, a team of personnel that understands the fundamental science as well as the scientific applications related to remote sensing is essential. Therefore, the workforce that will excel in this field requires individuals who not only have a strong academic background, but who also have practical hands-on experience with remotely sensed data, and have developed knowledge of its real-world applications. NASA's DEVELOP Program has played an integral role in fulfilling this need. DEVELOP is a NASA Science Mission Directorate Applied Sciences training and development program that extends the benefits of NASA Earth science research and technology to society

Fusion Learning Conference 2021 - Supplement

This is a supplement to the proceedings of the 2021 Fusion Learning Conference held at Bournemouth University in the UK and contains material not previously published

EURL ECVAM Status Report on the Development, Validation and Regulatory Acceptance of Alternative Methods and Approaches (2016)

Replacement, Reduction and Refinement of animal testing is anchored in EU legislation. Alternative non-animal approaches facilitate a shift away from animal testing. Cell-based methods and computational technologies are integrated to translate molecular mechanistic understanding of toxicity into safety testing strategies.JRC.F.3-Chemicals Safety and Alternative Method

Fusion Learning Colloquium 2022 - Proceedings

This is the proceedings of the 2022 Fusion Learning Colloquium held at Bournemouth University in the UK

The role of multihaem cytochromes in the respiration of nitrite in Escherichia coli and Fe(III) in \u3ci\u3eShewanella oneidensis\u3c/i\u3e

The periplasmic nitrite reductase system from Escherichia coli and the extracellular Fe (III) reductase system from Shewanella oneidensis contain multihaem c-type cytochromes as electron carriers and terminal reductases. The position and orientation of the haem cofactors in multihaem cytochromes from different bacteria often show significant conservation despite different arrangements of the polypeptide chain. We propose that the decahaem cytochromes of the iron reductase system MtrA, MtrC and OmcA comprise pentahaem ‘modules’ similar to the electron donor protein, NrfB, from E. coli. To demonstrate this, we have isolated and characterized the N-terminal pentahaem module of MtrA by preparing a truncated form containing five covalently attached haems. UV–visible spectroscopy indicated that all five haems were low-spin, consistent with the presence of bis-His ligand co-ordination as found in full-length MtrA

Review article: Part one: Goal-directed resuscitation - Which goals? Haemodynamic targets

The use of appropriate resuscitation targets or end-points may facilitate early detection and appropriate management of shock. There is a fine balance between oxygen delivery and consumption, and when this is perturbed, an oxygen debt is generated. In this narrative review, we explore the value of global haemodynamic resuscitation end-points, including pulse rate, blood pressure, central venous pressure and mixed/central venous oxygen saturations. The evidence supporting the reliability of these parameters as end-points for guiding resuscitation and their potential limitations are evaluated

Review article: Part two: Goal-directed resuscitation - Which goals? Perfusion targets

Haemodynamic targets, such as cardiac output, mean arterial blood pressure and central venous oxygen saturations, remain crude predictors of tissue perfusion and oxygen supply at a cellular level. Shocked patients may appear adequately resuscitated based on normalization of global vital signs, yet they are still experiencing occult hypoperfusion. If targeted resuscitation is employed, appropriate use of end-points is critical. In this review, we consider the value of directing resuscitation at the microcirculation or cellular level. Current technologies available include sublingual capnometry, video microscopy of the microcirculation and near-infrared spectroscopy providing a measure of tissue oxygenation, whereas base deficit and lactate potentially provide a surrogate measure of the adequacy of global perfusion. The methodology and evidence for these technologies guiding resuscitation are considered in this narrative review