Sizes of Viral Genomes and Strengths of Viral Capsids

William M. Gelbart和Charles M.加州大学洛杉矶分校的Knobler等人的研究得到了化学系实验物理化学和理论与计算化学项目以及分子与细胞生物科学系分子生物物理项目的资助。 他们正在进行一系列的实验和理论研究的大小和形状的大单链（ss）RNA分子，作为一个功能的核苷酸序列和长度。 具体来说，使用小角度X射线散射，荧光相关光谱和分析超离心技术的组合，他们正在测量数千个核苷酸长的RNA分子的回转半径和流体动力学半径，阐明生物进化与随机序列的影响。 他们还确定了病毒核衣壳自组装的效率，作为这些分子大小（半径）的函数，并测试了他们的理论想法，即病毒基因组序列已经进化为有效包装的紧凑结构。PI Gelbart和Knobler的研究计划显着推进了我们对大RNA分子结构的理解，这些分子广泛参与蛋白质的合成以及大多数植物和动物病毒的复制。 他们对病毒蛋白包装RNA的研究也为仿生纳米容器提供了丰富的新来源，其应用范围广泛，涉及生物标记，疫苗和基因的递送。 他们的研究生和博士后研究员以前接受过化学工程，生物化学/分子生物学或物理化学的培训，但现在是一个联合研究小组的一部分，为他们提供了跨越所有这些界限的独特的跨学科培训，包括理论和实验。

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.