Although RNA molecules are highly negatively charged, anions have been observed bound to RNA in crystal structures. It has been proposed that anion binding sites found within isolated RNAs represent ...regions of the molecule that could be involved in intermolecular interactions, indicating potential contact points for negatively charged amino acids from proteins or phosphate groups from an RNA. Several types of anion binding sites have been cataloged based on available structures. However, currently there is no method for unambiguously assigning anions to crystallographic electron density, and this has precluded more detailed analysis of RNA-anion interaction motifs and their significance. We therefore soaked selenate into two different types of RNA crystals and used the anomalous signal from these anions to identify binding sites in these RNA molecules unambiguously. Examination of these sites and comparison with other suspected anion binding sites reveals features of anion binding motifs, and shows that selenate may be a useful tool for studying RNA-anion interactions.
The Shame of It Gubrium, Erika K., Pellissery, Sony
12/2013
eBook
The shame experienced by people living in poverty has long been recognised. Nobel laureate and economist, Amartya Sen, has described shame as the "irreducible core" of poverty. However, little ...attention has been paid to the implications of this connection in the making and implementation of anti-poverty policies.
This important volume rectifies this critical omission and demonstrates the need to take account of the psychological consequences of poverty for policy to be effective. Drawing on pioneering empirical research in countries as diverse as Britain, Uganda, Norway, Pakistan, India, South Korea and China, it outlines core principles that can aid policy makers in policy development.
In so doing, it provides the foundation for a shift in policy learning on a global scale and bridges the traditional distinctions between North and South, and high-, middle- and low-income countries. This will help students, academics and policy makers better understand the reasons for the varying effectiveness of anti-poverty policies.
Raman crystallography is the application of Raman spectroscopy to single crystals. This technique has been applied to a variety of protein molecules where it has provided unique information about ...biopolymer folding, substrate binding, and catalysis. Here, we describe the application of Raman crystallography to functional RNA molecules. RNA represents unique opportunities and challenges for Raman crystallography. One issue that confounds studies of RNA is its tendency to adopt multiple non-functional folds. Raman crystallography has the advantage that it isolates a single state of the RNA within the crystal and can evaluate its fold, metal ion binding properties (ligand identity, stoichiometry, and affinity), proton binding properties (identity, stoichiometry, and affinity), and catalytic potential. In particular, base-specific stretches can be identified and then associated with the binding of metal ions and protons. Because measurements are carried out in the hanging drop at ambient, rather than cryo, conditions and because RNA crystals tend to be approximately 70% solvent, RNA dynamics and conformational changes become experimentally accessible. This review focuses on experimental setup and procedures, acquisition and interpretation of Raman data, and determination of physicochemical properties of the RNA. Raman crystallographic and solution biochemical experiments on the HDV RNA enzyme are summarized and found to be in excellent agreement. Remarkably, characterization of the crystalline state has proven to help rather than hinder functional characterization of functional RNA, most likely because the tendency of RNA to fold heterogeneously is limited in a crystalline environment. Future applications of Raman crystallography to RNA are briefly discussed.
A Raman microscope and Raman difference spectroscopy are used to detect the vibrational signature of RNA-bound magnesium hydrate in crystals of hepatitis delta virus (HDV) ribozyme and to follow the ...effects of magnesium hydrate binding to the nonbridging phosphate oxygens in the phosphodiester backbone. There is a correlation between the Raman intensity of the innersphere magnesium hydrate signature peak, near 322 cm−1, and the intensity of the PO2 − symmetric stretch, near 1100 cm−1, perturbed by magnesium binding, demonstrating direct observation of −PO2 −···Mg2+(H2O) x innersphere complexes. The complexes may be pentahydrates (x = 5) and tetrahydrates (x = 4). The assignment of the Raman feature near 322 cm−1 to a magnesium hydrate species is confirmed by isotope shifts observed in D2O and H2 18O that are semiquantitatively reproduced by calculations. The standardized intensity changes in the 1100 cm−1 PO2 − feature seen upon magnesium hydrate binding indicates that there are ∼5 innersphere Mg2+···−O2P contacts per HDV molecule when the crystal is exposed to a solution containing 20 mM magnesium.
Previous research has shown that looked after children and young people are vulnerable to poor life outcomes, including early pregnancy. Abigail Knight, Elaine Chase and Peter Aggleton discuss ...findings from a Department of Health-funded study on teenage pregnancy among young people in and leaving care. Using in-depth interviews, data were collected from 63 recently looked after young people aged 15 to 24 and from 78 associated professionals from a range of backgrounds, across four research sites. This paper focuses specifically on young people's experiences of foster care and the interface between foster care and the emotional influences surrounding pregnancy, opportunities for and challenges to learning about sex and relationships, and the provision of support during pregnancy and early parenthood. Findings suggest the need to provide foster carers with support, training and guidance concerning relevant and appropriate education for young people with regard to sex and relationships. The findings also indicate the need for specialist guidance on these matters in mother and baby foster care placements so as to benefit foster carers, young parents and their babies alike.
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