Open AccessStructural Studies of Encephalomyocarditis Virus RNA both in situ and in Free Solution
Author(s) -
David Frisby,
Rosalind I. Cotter,
B. M. Richards
Publication year - 1977
Publication title -
journal of general virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.55
H-Index - 167
eISSN - 1465-2099
pISSN - 0022-1317
DOI - 10.1099/0022-1317-37-2-311
Subject(s) - capsid , rna , virus , biology , nucleotide , covalent bond , circular dichroism , virology , biophysics , crystallography , biochemistry , microbiology and biotechnology , chemistry , gene , organic chemistry
The secondary structure of encephalomyocarditis (EMC) virus RNA has been studied in situ and in free solution by absorbance-temperature relationships and by circular dichroism (CD). Extracted EMC virus RNA melts reversibly and has a hypochromicity of about 20%; analysis of CD spectra and formaldehyde treatment suggests that approx. 60% of the nucleotides are involved in base-pairing at 25 degrees C. It is shown that the RNA within the virus particle is less structured than when it exists in free solution, being partially stabilized by capsid protein against melting until the virion is disrupted to release the intact RNA. Upon clarification to remove denatured capsid protein, the released RNA gives a melting profile identical with that of phenol-extracted virus RNA. The results suggest that the intact structure of the virus is dependent upon intimate non-covalent bonds between RNA and protein together with hydrophobic bonds between the protein subunits.