Polyamines in bacteriophage R17 and its RNA

Abstract

Bacteriophage R17 and its RNA were found to contain significant amounts of spermidine but not of putrescine. When isolated at 0.01 M KCl, up to 1,000 molecules of spermidine were associated with the virion. The phage RNA isolated with phenol plus sodium lauryl sulfate contained approximately 70 to 90 molecules of spermidine. The association appeared to be ionic because the bound spermidine could be dissociated by KCI, MgCl2, or both. Effects of polyamines on in vitro translation were studied using both poly(U) and phage R17-RNA as mRNA. Addition of spermidine to the system at suboptimal concentrations of Mg2+ resulted in marked stimulations of the rate of protein synthesis. Putrescine alone had no effect but stimulated the incorporation in the presence of suboptimal concentrations of spermidine plus Mg2+. The isolated amino acid-incorporating system contained suboptimal soluble and bound polyamines. A comparison of incorporation was made in this system using R17-RNA with and without bound spermidine. No effects of these bound cations were detected on the rate or extent of incorporation of valine. The ratio of incorporation of histidine (present in noncoat proteins) to valine (total protein) revealed little difference as a function of cation in the system or as a function of the spermidine present in R17-RNA.

Interferon-Induced Spermidine-Spermine Acetyltransferase and Polyamine Depletion Restrict Zika and Chikungunya Viruses

“…Polyamines are ubiquitous molecules found in all cells at concentrations up to 1 mM (Igarashi and Kashiwagi, 2000); thus, viruses may have evolved a dependence on polyamines. Polyamines are enriched in virions of bacteriophage T7 (Fukuma and Cohen, 1975), herpes simplex virus 1 (Gibson and Roizman, 1971), and vaccinia (Lanzer and Holowczak, 1975), among others (Fukuma and Cohen, 1975;Gibson and Roizman, 1971;Lanzer and Holowczak, 1975), but not within the virion of the RNA virus Semliki Forest virus (Raina et al, 1981). For DNA viruses, polyamines facilitate viral assembly of HCMV virions (Gibson et al, 1984), DNA-dependent RNA polymerase activity in vaccinia virus (Moussatché , 1985), and DNA synthesis in HSV-1 (Pohjanpelto et al, 1988).…”

“…The viral capsids of herpesviruses contain polyamines that putatively neutralize charges on viral DNA to facilitate compaction and encapsidation (Gibson and Roizman, 1971). Vaccinia (Lanzer and Holowczak, 1975) and bacteriophage R17 (Fukuma and Cohen, 1975) were also shown to incorporate polyamines into virions. While RNA viruses could potentially use similar mechanisms to neutralize nucleic acids, studies on Semliki Forest virus demonstrated that polyamines are not enriched in the viral capsid (Raina et al, 1981).…”

Polyamine Metabolism and Oxidative Protein Folding in the ER as ROS-Producing Systems Neglected in Virology

“…Virions from densonucleosis viruses 1 and 2 contain putrescine, spermidine, and spermine comprising 1.41% ( w / w ) of the virus particle and neutralizing 26% of the single-stranded viral DNA [ 129 ]. Vaccinia virus of the Poxviridae family [ 130 ] and bacteriophage R17 [ 131 ] also incorporate polyamines into virions. Encephalomyocarditis virus contains approximately 200 molecules of putrescine, 100 molecules of spermidine, and 40 molecules of spermine that neutralize 11% of the negative charge of the viral genome [ 132 ].…”

Hydrodynamic properties of RNA: effect of multivalent cations on the sedimentation behavior of turnip yellow mosaic virus RNA

“…It has been claimed that the RNA phage R17 contains about 1000 molecules of spermidine which are sufficient to neutralize the phosphate groups completely. A certain fraction of these ions remains bound to the RNA after isolation depending on the conditions used (Fukuma & Cohen, 1975). The presence of a chelating agent like EDTA will not be sufficient to overcome the above-mentioned problems, so dialysis of the RNA solutions and dilution with dialysate should be necessary steps in the physicochemical characterization of natural RNAs.…”