Circular Dichroism Studies of Chicory Yellow Mottle Virus

Abstract

SUMMARYA spectroscopic characterization is given of the isometric RNA-containing chicory yellow mottle virus. The circular dichroism of the virus is close to the sum of that of the native RNA and protein components. The nucleic acid structure is formed by regions of single-chain stacked-base helices similar to that of poly(A) at neutral pH, and short double-helical loops, while the conformation of the capsid is largely accounted for by regions of fl-form and random-chain structures.The heat-induced dissociation of virus nucleoprotein occurs concomitantly with destabilization of the orderly structures of the protein moiety, indicating that only minor interactions between RNA and protein occur. It is suggested that interactions between RNA and protein could involve some aromatic residues of the capsid and the heterocyclic bases of the nucleic acid.

Densonucleosis Virus Structural Proteins

“…To determine whether a conformational difference occurred in the coat when present in top component or in part of the virus particle, circular dichroism studies were performed, and differences were detected. Analysis of the results by standard methods failed to demonstrate that the virus protein existed in a predominant secondary structural form (similar observations have been made for other singlestranded RNA viruses [11,28,31]. Interaction of single-stranded nucleic acid with the protein induced a marked change in optical properties of the protein, nucleic acid, or both.…”

Spectroscopic Studies on Purified Particles and Isolated RNA of Cucumber Mosaic Virus

“…Circular dichroism (CD) spectroscopy has been used to investigate plant virus structure and stability (Isenberg et al, 1971: Incardona et al, 1973Piazzolla et al, 1977b;Tamburro et al, 1978;Denloye et al, 1978;Odumosu et al, 1981). CMV particles seemed to be particularly interesting because of the presence of the satellite RN A and the recent proposal that it interacts with CMV by a mechanism that inhibits viral RNA replication (Kaper, 1984).…”