William M. Gelbart and Charles M. Knobler of the University of California, Los Angeles are supported by an award from the Experimental Physical Chemistry and Theoretical and Computational Chemistry Programs of the Chemistry Division and the Molecular Biophysics Program of the Division of Molecular and Cellular Biosciences. They are carrying out a series of experimental and theoretical studies on the sizes and shapes of large single-stranded (ss) RNA molecules, as a function of nucleotide sequence and length. Specifically, using a combination of small-angle X-ray scattering, fluorescence correlation spectroscopy and analytical ultra-centrifugation techniques, they are measuring the radii of gyration and hydrodynamic radii of many-thousand-nucleotide-long RNA molecules, elucidating the effects of biologically-evolved vs random sequences. They are also determining the efficiencies of self-assembly of viral nucleocapsids as a function of the sizes (radii) of these molecules and testing their theoretical idea that viral genome sequences have evolved to give compact structures for efficient packaging.
The research program of PIs Gelbart and Knobler is significantly advancing our understanding of the structure of large RNA molecules that are widely involved in the synthesis of proteins and in the replication of most plant and animal viruses. Their studies of the packaging of RNA by viral proteins are also providing a rich new source of biomimetic nanocontainers, with a wide range of applications involving the delivery of biolabels, vaccines, and genes. Their graduate students and postdoctoral fellows have been trained previously in either chemical engineering, biochemistry/molecular biology, or physical chemistry, but are now part of a joint research group that offers them a uniquely interdisciplinary training across all of these boundaries, and in both theory and experiment.
