Structure determination of large RNA motifs – Dr Vasudevan Ramesh
Award of beam time access at the Synchrotron Diamond Light Source Facility, Didcot, Oxfordshire
Following technical feasibility clearance by the Synchrotron Radiation Circular Dichroism Spectroscopy Facility at Diamond Light Source, the external peer review panel considered our research proposal and have awarded beam time access (2015-16) to characterise the structure of large RNA motifs of biological significance, e.g. 88mer RNA duplex shown below. The award will help elucidate the secondary structure and interactions of a range of conserved internal secondary structural motifs such as helical stems, loops, bulges, four-way junctions etc of RNAs which are implicated in binding to antibiotics, proteins and other RNAs. An interesting feature of these large RNA motifs is that they have high conformational mobility at different time scales and thus it is not straightforward to apply conventional high resolution techniques such as NMR even with isotopic labelling (expensive) and very high magnetic fields. However, the application of synchrotron circular dichroism (CD) spectroscopy offers a complementary method to NMR. The high photon flux at Diamond Light Source will offer several orders of magnitude greater sensitivity and wide wavelength range (140 – 700nm) than commercial instruments resulting in shorter measurement time to characterise both canonical and non-canonical RNA secondary structural motifs and their interactions.