Formaldehyde-induced tight binding of protein to RNA in particles of rod-like viruses. Nature and specificity of the crosslinks
Kiseleva, N.P.; Khromov, I.S.; Kust, S.V.; Shemiakin, I.G.; Dobrov, E.N.
Biokhimiia 46(11): 2019-2023
1981
ISSN/ISBN: 0320-9725 PMID: 7317529 Document Number: 179506
A stable RNA-protein complex was obtained by treatment of a helical tobacco masaic virus-like virus cucumber virus 4 (CV4), with 1.5% formaldehyde at 50.degree. C and stability and specificity of the RNA-protein bonds in the complex was studied. After alkaline T2-RNase hydrolysis of the complex obtained from [32P]-labeled CV4, the RNA-protein crosslinks were identified by the presence of [32P] in the protein band during sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The resistance of the crosslinks to boiling in 2% SDS with 0.2% mercaptoethanol, to 0.3 N KOH and to 10% trichloracetic acid is indicative of the covalent nature of the nucleotide-protein bonds in the CV complex. Data from tryptic peptide map analysis suggest that not more than 3 peptides within the complex contain the [32P] label. Formaldehyde apparently crosslinks to the intravirus RNA only at the specific site(s) of the CV protein molecule.