Mammalian circadian clocks are driven by transcription/translation feedback loops composed of positive transcriptional activators (BMAL1 and CLOCK) and negative repressors (CRYPTOCHROMEs (CRYs) and PERIODs (PERs)). CRYs, in complex with PERs, bind to the BMAL1/CLOCK complex and repress E-box–driven transcription of clock-associated genes. There are two individual CRYs, with CRY1 exhibiting higher affinity to the BMAL1/CLOCK complex than CRY2. It is known that this differential binding is regulated by a dynamic serine-rich loop adjacent to the secondary pocket of both CRYs, but the underlying features controlling loop dynamics are not known. Here we report that allosteric regulation of the serine-rich loop is mediated by Arg-293 of CRY1, identified as a rare CRY1 SNP in the Ensembl and 1000 Genomes databases. The p.Arg293His CRY1 variant caused a shortened circadian period in a Cry1−/−Cry2−/− double knockout mouse embryonic fibroblast cell line. Moreover, the variant displayed reduced repressor activity on BMAL1/CLOCK driven transcription, which is explained by reduced affinity to BMAL1/CLOCK in the absence of PER2 compared with CRY1. Molecular dynamics simulations revealed that the p.Arg293His CRY1 variant altered a communication pathway between Arg-293 and the serine loop by reducing its dynamicity. Collectively, this study provides direct evidence that allosterism in CRY1 is critical for the regulation of circadian rhythm.

CARM1 is a protein arginine methyltransferase (PRMT) that acts as a coactivator in a number of transcriptional programs. CARM1 orchestrates this coactivator activity in part by depositing the H3R17me2a histone mark in the vicinity of gene promoters that it regulates. However, the gross levels of H3R17me2a in CARM1 KO mice did not significantly decrease, indicating that other PRMT(s) may compensate for this loss. We thus performed a screen of type I PRMTs, which revealed that PRMT6 can also deposit the H3R17me2a mark in vitro. CARM1 knockout mice are perinatally lethal and display a reduced fetal size, whereas PRMT6 null mice are viable, which permits the generation of double knockouts. Embryos that are null for both CARM1 and PRMT6 are noticeably smaller than CARM1 null embryos, providing in vivo evidence of redundancy. Mouse embryonic fibroblasts (MEFs) from the double knockout embryos display an absence of the H3R17me2a mark during mitosis and increased signs of DNA damage. Moreover, using the combination of CARM1 and PRMT6 inhibitors suppresses the cell proliferation of WT MEFs, suggesting a synergistic effect between CARM1 and PRMT6 inhibitions. These studies provide direct evidence that PRMT6 also deposits the H3R17me2a mark and acts redundantly with CARM1.

The molecular mechanisms of reduced frataxin (FXN) expression in Friedreich's ataxia (FRDA) are linked to epigenetic modification of the FXN locus caused by the disease-associated GAA expansion. Here, we identify that SUV4-20 histone methyltransferases, specifically SUV4-20 H1, play an important role in the regulation of FXN expression and represent a novel therapeutic target. Using a human FXN–GAA–Luciferase repeat expansion genomic DNA reporter model of FRDA, we screened the Structural Genomics Consortium epigenetic probe collection. We found that pharmacological inhibition of the SUV4-20 methyltransferases by the tool compound A-196 increased the expression of FXN by ∼1.5-fold in the reporter cell line. In several FRDA cell lines and patient-derived primary peripheral blood mononuclear cells, A-196 increased FXN expression by up to 2-fold, an effect not seen in WT cells. SUV4-20 inhibition was accompanied by a reduction in H4K20me2 and H4K20me3 and an increase in H4K20me1, but only modest (1.4–7.8%) perturbation in genome-wide expression was observed. Finally, based on the structural activity relationship and crystal structure of A-196, novel small molecule A-196 analogs were synthesized and shown to give a 20-fold increase in potency for increasing FXN expression. Overall, our results suggest that histone methylation is important in the regulation of FXN expression and highlight SUV4-20 H1 as a potential novel therapeutic target for FRDA.

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DNA polymerases are today used throughout scientific research, biotechnology, and medicine, in part for their ability to interact with unnatural forms of DNA created by synthetic biologists. Here especially, natural DNA polymerases often do not have the “performance specifications” needed for transformative technologies. This creates a need for science-guided rational (or semi-rational) engineering to identify variants that replicate unnatural base pairs (UBPs), unnatural backbones, tags, or other evolutionarily novel features of unnatural DNA. In this review, we provide a brief overview of the chemistry and properties of replicative DNA polymerases and their evolved variants, focusing on the Klenow fragment of Taq DNA polymerase (Klentaq). We describe comparative structural, enzymatic, and molecular dynamics studies of WT and Klentaq variants, complexed with natural or noncanonical substrates. Combining these methods provides insight into how specific amino acid substitutions distant from the active site in a Klentaq DNA polymerase variant (ZP Klentaq) contribute to its ability to replicate UBPs with improved efficiency compared with Klentaq. This approach can therefore serve to guide any future rational engineering of replicative DNA polymerases.

RecQ family helicases are highly conserved from bacteria to humans and have essential roles in maintaining genome stability. Mutations in three human RecQ helicases cause severe diseases with the main features of premature aging and cancer predisposition. Most RecQ helicases shared a conserved domain arrangement which comprises a helicase core, an RecQ C-terminal domain, and an auxiliary element helicase and RNaseD C-terminal (HRDC) domain, the functions of which are poorly understood. In this study, we systematically characterized the roles of the HRDC domain in E. coli RecQ in various DNA transactions by single-molecule FRET. We found that RecQ repetitively unwinds the 3'-partial duplex and fork DNA with a moderate processivity and periodically patrols on the ssDNA in the 5'-partial duplex by translocation. The HRDC domain significantly suppresses RecQ activities in the above transactions. In sharp contrast, the HRDC domain is essential for the deep and long-time unfolding of the G4 DNA structure by RecQ. Based on the observations that the HRDC domain dynamically switches between RecA core- and ssDNA-binding modes after RecQ association with DNA, we proposed a model to explain the modulation mechanism of the HRDC domain. Our findings not only provide new insights into the activities of RecQ on different substrates but also highlight the novel functions of the HRDC domain in DNA metabolisms.

Myosins generate force and motion by precisely coordinating their mechanical and chemical cycles, but the nature and timing of this coordination remains controversial. We utilized a FRET approach to examine the kinetics of structural changes in the force-generating lever arm in myosin V. We directly compared the FRET results with single-molecule mechanical events examined by optical trapping. We introduced a mutation (S217A) in the conserved switch I region of the active site to examine how myosin couples structural changes in the actin- and nucleotide-binding regions with force generation. Specifically, S217A enhanced the maximum rate of lever arm priming (recovery stroke) while slowing ATP hydrolysis, demonstrating that it uncouples these two steps. We determined that the mutation dramatically slows both actin-induced rotation of the lever arm (power stroke) and phosphate release (≥10-fold), whereas our simulations suggest that the maximum rate of both steps is unchanged by the mutation. Time-resolved FRET revealed that the structure of the pre– and post–power stroke conformations and mole fractions of these conformations were not altered by the mutation. Optical trapping results demonstrated that S217A does not dramatically alter unitary displacements or slow the working stroke rate constant, consistent with the mutation disrupting an actin-induced conformational change prior to the power stroke. We propose that communication between the actin- and nucleotide-binding regions of myosin assures a proper actin-binding interface and active site have formed before producing a power stroke. Variability in this coupling is likely crucial for mediating motor-based functions such as muscle contraction and intracellular transport.

Centrioles are key eukaryotic organelles that are responsible for the formation of cilia and flagella, and for organizing the microtubule network and the mitotic spindle in animals. Centriole assembly requires oligomerization of the essential protein spindle assembly abnormal 6 (SAS-6), which forms a structural scaffold templating the organization of further organelle components. A dimerization interaction between SAS-6 N-terminal “head” domains was previously shown to be essential for protein oligomerization in vitro and for function in centriole assembly. Here, we developed a pharmacophore model allowing us to assemble a library of low-molecular-weight ligands predicted to bind the SAS-6 head domain and inhibit protein oligomerization. We demonstrate using NMR spectroscopy that a ligand from this family binds at the head domain dimerization site of algae, nematode, and human SAS-6 variants, but also that another ligand specifically recognizes human SAS-6. Atomistic molecular dynamics simulations starting from SAS-6 head domain crystallographic structures, including that of the human head domain which we now resolve, suggest that ligand specificity derives from favorable Van der Waals interactions with a hydrophobic cavity at the dimerization site.

RNA-protein interfaces control key replication events during the HIV-1 life cycle. The viral trans-activator of transcription (Tat) protein uses an archetypal arginine-rich motif (ARM) to recruit the host positive transcription elongation factor b (pTEFb) complex onto the viral trans-activation response (TAR) RNA, leading to activation of HIV transcription. Efforts to block this interaction have stimulated production of biologics designed to disrupt this essential RNA-protein interface. Here, we present four co-crystal structures of lab-evolved TAR-binding proteins (TBPs) in complex with HIV-1 TAR. Our results reveal that high-affinity binding requires a distinct sequence and spacing of arginines within a specific β2-β3 hairpin loop that arose during selection. Although loops with as many as five arginines were analyzed, only three arginines could bind simultaneously with major-groove guanines. Amino acids that promote backbone interactions within the β2-β3 loop were also observed to be important for high-affinity interactions. Based on structural and affinity analyses, we designed two cyclic peptide mimics of the TAR-binding β2-β3 loop sequences present in two high-affinity TBPs (KD values of 4.2 ± 0.3 and 3.0 ± 0.3 nm). Our efforts yielded low-molecular weight compounds that bind TAR with low micromolar affinity (KD values ranging from 3.6 to 22 μm). Significantly, one cyclic compound within this series blocked binding of the Tat-ARM peptide to TAR in solution assays, whereas its linear counterpart did not. Overall, this work provides insight into protein-mediated TAR recognition and lays the ground for the development of cyclic peptide inhibitors of a vital HIV-1 RNA-protein interaction.

Erythromycin-resistance methyltransferases are SAM dependent Rossmann fold methyltransferases that convert A2058 of 23S rRNA to m6 2A2058. This modification sterically blocks binding of several classes of antibiotics to 23S rRNA, resulting in a multidrug-resistant phenotype in bacteria expressing the enzyme. ErmC is an erythromycin resistance methyltransferase found in many Gram-positive pathogens, whereas ErmE is found in the soil bacterium that biosynthesizes erythromycin. Whether ErmC and ErmE, which possess only 24% sequence identity, use similar structural elements for rRNA substrate recognition and positioning is not known. To investigate this question, we used structural data from related proteins to guide site-saturation mutagenesis of key residues and characterized selected variants by antibiotic susceptibility testing, single turnover kinetics, and RNA affinity–binding assays. We demonstrate that residues in α4, α5, and the α5-α6 linker are essential for methyltransferase function, including an aromatic residue on α4 that likely forms stacking interactions with the substrate adenosine and basic residues in α5 and the α5-α6 linker that likely mediate conformational rearrangements in the protein and cognate rRNA upon interaction. The functional studies led us to a new structural model for the ErmC or ErmE-rRNA complex.

V. G. Lysov
Trans. Moscow Math. Soc. 83 (), 291-304.
Abstract, references and article information

A. I. Aptekarev and M. L. Yattselev
Trans. Moscow Math. Soc. 83 (), 251-268.
Abstract, references and article information

L. Oeding
Trans. Moscow Math. Soc. 83 (), 227-250.
Abstract, references and article information

A. V. Domrina
Trans. Moscow Math. Soc. 83 (), 201-215.
Abstract, references and article information

A. V. Silantyev
Trans. Moscow Math. Soc. 83 (), 75-149.
Abstract, references and article information

A. G. Sergeev, A. Kh. Khachatryan and Kh. A. Khachatryan
Trans. Moscow Math. Soc. 83 (), 55-65.
Abstract, references and article information

N. R. Ikonomov and S. P. Suetin
Trans. Moscow Math. Soc. 83 (), 33-54.
Abstract, references and article information

Mining and the Circular Economy: Implications for the Minerals and Metals Industries 6 November 2017 — 4:00PM TO 5:30PM Anonymous (not verified) 31 October 2017 Chatham House, London

Visualizing the Data: The Evolution of Trade Tensions in Metals and Minerals Markets 18 January 2018 — 4:30PM TO 6:00PM Anonymous (not verified) 19 December 2017 Chatham House, London

Over the past decade, producer countries such as South Africa, Zambia, Indonesia, the DRC and, most recently, Tanzania have restricted exports of unprocessed precious metals, copper, nickel, cobalt and other minerals in an attempt to support, or create, downstream processing industries and jobs or increase revenues. These moves have invariably created tensions with trading partners. Research suggests that export restrictions are not the best way to achieve such policy objectives and can instead harm the producer country’s economy and undermine the functioning of international metals and minerals.

Drawing on OECD and Chatham House research on resource trade, the speaker will present analysis and data visualizations exploring the drivers of past export restrictions and their political and economic impacts. They will also consider how the drivers of ‘resource nationalist measures’ are changing, whether and where export restrictions might present strategic and economic risks in the current context, and the extent to which producer and consumer governments and international governance mechanisms are prepared to address them.

Attendance at this event is by invitation only.

Fossil Fuels Expert Roundtable: How Solar is Shaping the Energy Transition 1 June 2018 — 9:00AM TO 10:30AM Anonymous (not verified) 22 May 2018 Chatham House, London

As global temperatures rise and extreme weather events multiply, doubts over the reality and imminence of climate change have dissipated. Despite this, there is a clear lack of urgency by governments to the approaching crisis. At this event, Prem Shankar Jha will set out what he believes are the three main causes for this inaction.

Furthermore, he will argue that catastrophic climate change is imminent, but even if it weren’t, the risk is too great to ignore. Only a complete shift from fossil fuels by 2070 at the latest would provide reasonable certainty of avoiding irreversible consequences. This transition is not only possible but the technologies to enable it were harnessed four to nine decades ago – and all of them draw their primary energy from the sun. These technologies are already capable of delivering electricity, transport fuels, and petrochemicals at prices that are competitive with the current delivered cost of electricity in the US and Western Europe. So what is holding up the energy shift?

Attendance at this event is by invitation only.

A New Era for China: Implications for the Global Mining and Metals Industries 18 June 2018 — 9:00AM TO 10:30AM Anonymous (not verified) 8 June 2018 Chatham House, London

Since the turn of the century, China’s demand for resources has dominated global headlines. It’s rapid demand growth through the early 2000s sparked the beginning of the commodities ‘super cycle’, and encouraged a growing Chinese presence in international mining, and in global metals and minerals markets. More recently, its transition toward the ‘new normal’ of slower but higher quality growth has underpinned the sudden slowdown in global commodities demand.

Drawing on China’s domestic ambitions, as set out in the 19th party congress, and on its wider strategic ambitions through the Belt and Road Initiative, the speaker will set out his thoughts on China’s next era of growth, and its likely implications for international mining investment and global metals and minerals markets.

Realizing the Potential of Extractives for Industrial and Economic Development 18 October 2018 — 5:30PM TO 7:00PM Anonymous (not verified) 3 October 2018 Chatham House | 10 St James's Square | London | SW1Y 4LE

Over the past two decades, the extractives industries have risen in importance for many low- and middle- income countries their prospects for economic development and poverty reduction. During a period of rising commodities prices, the development of extractives became increasingly attractive to both governments and companies. There was - and remains - much discussion about their potential to support inclusive development.

However, there are also risks and uncertainties associated with the extractives industries and many things can, and do, go wrong. Fluctuations in commodity prices can be hard to manage and can lead to considerable fiscal pressures. In the longer-term, climate change and the various policy responses to this, will profoundly affect the extractives sector as renewables replace fossil fuels in the global energy mix.

Managing the extractives sectors will therefore remain highly challenging especially in low-income countries where institutions are often weak. This roundtable will bring together some of the foremost academics and practitioners working in the extractives industries and also in economic development to discuss a major new UNU-WIDER study Extractive Industries: The Management of Resources as a Driver of Sustainable Development.

Attendance at this event is by invitation only.

The Electric Vehicle Revolution: Impacts on Oil Economies and Industry 24 January 2019 — 8:15AM TO 9:45AM Anonymous (not verified) 3 December 2018 Chatham House | 10 St James's Square | London | SW1Y 4LE

Electric vehicle (EV) deployment is gathering pace: the Norwegian government thinks that EV subsidies will be unnecessary by 2025 as they reach parity with diesel and petrol vehicles.

China has stipulated that EVs comprise 12 per cent of vehicle sales by 2020 while more governments are committing to banning diesel and petrol vehicles.

These developments are expected to be replicated as urban air pollution rises up the political agenda while technological developments and falling costs have given rise to ambitious forecasts on the increase in the deployment of EVs and the demise of the internal combustion engine.

Considering this, the presentations and initial discussion focus on:

• The influence of new technologies on the automotive landscape, including autonomous vehicles.
• How the automotive and oil companies are adjusting their business models to accommodate and encourage the rise in EVs.
• The risks and opportunities for the deployment of EVs for incumbents and new market actors.
• The role of government for example in public procurement and infrastructure development.
• The potential for modal shift and its impact on oil demand.

The discussion then seeks to explore the need for benchmarks of change including data and metrics to understand the changing risk landscape and the implications for different actors.

Finally, the discussion focuses on the speed of transformation and what this means for existing and new market actors.

The Impact of Brexit on Energy Transformation in the UK and EU 28 March 2019 — 8:15AM TO 9:45AM Anonymous (not verified) 3 December 2018 Chatham House | 10 St James's Square | London | SW1Y 4LE

The UK’s decision to leave the EU will fundamentally reshape many of the UK’s policies and its relations with countries around the world. For energy and climate, the changes could be significant and will need to be managed carefully to secure ongoing investment, stable energy prices and ambitious climate objectives. The UK’s departure will also affect the balance of political support for climate and energy policies with the EU institutions and potentially impact upon regional initiatives.

This roundtable will discuss:

• The impact on the energy sector of Brexit during the transition period through until December 2020 including the operation of interconnectors and access to the Internal energy market, ongoing engagement in European research collaboration and the replacement of European financial resources.
• The possible opportunities and risks for the UK’s energy sector in 2021 and beyond.
• The implications of Brexit on the EU’s energy and climate policy.

The roundtable will discuss the role of the public and business in shaping the future deal as it will need to be ratified by the parliaments of all member states.

Attendance at this event is by invitation only.

The Global Implications of China's Energy Revolution 4 March 2019 — 9:00AM TO 10:30AM Anonymous (not verified) 7 February 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

Ten years ago, it would have been difficult to believe that China – the world’s largest greenhouse gas emitter – would be one of the global leaders in some elements of clean energy development and deployment. With increasing air pollution and predominantly coal-fired power generation fueled by a booming economy and population, China has had to rethink its approach to environmental protection and climate mitigation.

Strong government signalling and national policies have led to the construction of the world’s largest fleets, wind farms and solar photovoltaic arrays in an effort to reduce national GDP intensities of energy and CO2 emissions. How has the availability of large amounts of capital, and the number of state-owned companies with soft budgetary constraints, helped contribute to this?

Against this backdrop, this event will consider how China must re-evaluate its approach to energy security – coal made up the majority of the country’s energy in 2016, followed by oil, of which 65 per cent had to be imported – despite the country being one of the pioneers of renewable energy. This event will look at how, in delivering on its clean energy objectives, China could redefine the traditional energy security paradox and in fact become more resilient to previously overlooked vulnerabilities.

The Future of Food Post-Brexit 26 February 2019 — 9:00AM TO 10:30AM Anonymous (not verified) 7 February 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

For almost half a century, the UK’s food system – comprising the totality of food production, transport, manufacturing, retailing and consumption – has been intrinsically and intricately linked to its membership of the European Community and, subsequently, the EU. Arguably, for no other sectors are the challenges and opportunities of Brexit as extensive as they are for UK food and agriculture.

Reforming the UK’s food system won’t be easy. The tight Brexit timeline, the complexities of negotiations and the political pressure to secure new trade deals could lead to decisions that are poorly conceived and become near impossible to correct.

This event will explore the challenges of the UK’s ‘just in time’ food system which only maintains 5-10 days’ worth of groceries country-wide, what the impacts of structural changes will be post-Brexit such as longer inspections of food imports at the border and what the main priorities for policymakers should be in the event of a no-deal Brexit to ensure the country’s food-stock can satisfy demand.

Plant-based 'Meat' and Cultured Meat: Revolutionizing the Livestock Sector 10 April 2019 — 4:00PM TO 5:30PM Anonymous (not verified) 14 March 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

Consensus is building across the scientific, environmental and public health communities that a radical shift away from excessive meat-eating patterns is urgently needed to tackle the unsustainability of the livestock sector. Recognizing the scale of the challenge ahead, public policymakers, civil society and innovators have increasingly sought to prompt shifts in consumer food choices – away from the most resource-intensive meat products and towards more sustainable alternatives.

Meat analogues – plant-based ‘meat’ and cultured meat also known as ‘lab-grown’ meat – mark a departure from traditional meat alternatives. Both are intended to be indistinguishable from – and in the case of cultured meat biologically equivalent to – animal-derived meat and are marketed principally at meat-eaters. Innovation and investment in meat analogues have increased significantly, but the direction and pace of growth in the meat analogue industry will depend upon a multitude of factors, including public acceptance, civil society support and incumbent industry responses.

This event will explore the challenges of scaling up production and generating demand for meat alternatives. It will also look at the ways policymakers in the UK and EU can impact the direction of the industry while examining what factors will influence consumer acceptance of plant-based ‘meat’ and cultured meat as substitutes for animal-derived meat.

The EU’s Un-Common Agricultural Policy 21 October 2019 — 8:30AM TO 10:00AM Anonymous (not verified) 27 September 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

Impact of the US Election on Global Climate Politics 25 November 2020 — 1:00PM TO 2:00PM Anonymous (not verified) 16 November 2020 Online

Panellists discuss how Joe Biden’s victory will impact international efforts to tackle climate change. Will climate finally become a common area for global cooperation?

Joe Biden’s victory over Donald Trump is already having a positive impact on international efforts to tackle climate change. Leaders from across the world, including the UK, Canada, Australia and Fiji, have used their first messages to the President-elect to draw attention to the climate crisis.

Biden has promised to re-join the global community in its commitment to the Paris Agreement – but this could be the easy part. More difficult will be whether and how Biden is able to deliver his ambitious climate plan, and how effectively he is able to integrate climate change into foreign policy efforts and national security strategies.

Global climate action has also moved forward in the last four years. The European Union recently pledged to become climate neutral by 2050, and China, Japan and South Korea have committed to achieving carbon neutral economies.

How will the US re-enter this global landscape of distributed leadership and what difficulties does it face? Will the US be willing to work within a competitive partnership with the EU and China? How will Biden’s win change the dynamic of COP26 next year? 

Moving Food up the Political Agenda 14 December 2020 — 3:00PM TO 4:30PM Anonymous (not verified) 8 December 2020 Online

How can food system transformation be woven into high level biodiversity, nutrition and climate forums in 2021?

Adverse impacts on food security are expected to worsen as global temperatures continue to rise. As well as feeling the impacts of climate change, food systems drive it in a number of ways. Not only do food systems contribute more to greenhouse gas emissions than any other parts of our lives, they are also the leading driver of biodiversity loss, the largest cause of deforestation and occupy the most land globally.

On our current trajectory, 1.5°C of warming could become a reality in the next 5-10 years. Transforming food systems to meet climate, biodiversity and food security goals is crucial. If left to continue, food alone could take us over 1.5°C this century – even with maximum efforts in the energy sector.

Unprecedented levels of action to transform food systems is required over the next decade. The coming year is described as a ‘super year’ given the numerous high-level global events taking place that cover climate, biodiversity and food security. The year ahead has also been identified as the final opportunity to bring global commitments in line with the goals of the Paris Agreement.

What can be achieved in the super year? How can food system transformation be woven into high level biodiversity, nutrition and climate forums during the super year? How can momentum from the super year be built upon, to ensure meaningful action is taken over the next decade?