Molecular interactions in viruses investigated by Raman spectroscopy: the chromosome and capsid of bacterial virus P22

摘要

Abstract: Laser Raman scattering is the method of choice for probing macromolecular structures and interactions in complex biological assemblies. The Raman technique is a valuable complement to high-resolution structure methods applied to biological molecules in the crystal (x-ray crystallography) and to static and dynamic light scattering methods applicable to solutions. Raman spectroscopy is particularly well suited to investigating assembly mechanisms of viruses and conformations of their nucleic acid and protein constituents. Here we describe the use of digital difference Raman methods to probe structures of the double-stranded (ds) DNA genome of the icosahedral virus P22 in packaged and unpackaged states. The findings are compared with structural changes in protein subunits of the P22 viral capsid, attendant with capsid expansion and DNA packaging. We find no evidence in the Raman spectrum of specific intermolecular interactions involving capsid protein and major groove sites of the packaged DNA. The present results suggest a simple model for organization of condensed dsDNA chromosomes in icosahedral viruses. !17