Intact ribonucleic acid from defective particles of bacteriophage R17

Argetsinger, Joan E.; Gussin, Gary N.

doi:10.1016/0022-2836(66)90016-7

Cited by 82 publications

(30 citation statements)

References 11 publications

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“…13,47 Sedimentation gradient analysis of versions of MS2 containing mutations in the A protein indicate that the A protein is also necessary for RNA packing (or compaction within the virion). 16 MS2 viruses with mutations in the A protein, in contrast to the wild-type MS2 virus, contain RNA that dangles outside of the protein shell and is sensitive to the action of nucleases. 16,17 Therefore, with respect to the life-cycle of the MS2 virus coat protein shell, in its pre-infection state, the protein shell contains the A protein, but postinfection, the A protein is absent.…”

Section: Discussionmentioning

confidence: 97%

“…Mutant viruses that lack the A protein contain loosely packed RNA that protrudes from the protein shell and then becomes degraded by nucleases in the medium. 16,17 Recent cryo-EM analysis of the MS2 virus reveals a network of RNA bound to the inner surface of the protein shell, which forms an icosahedron with RNA-free holes at the 5-fold axis and the quasi 6-fold axis. This ordered RNA, which is thought to represent only a subset of the genomic RNA, is presumably attached to the coat protein dimers via RNA stem-loop motifs.…”

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confidence: 99%

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The MS2 Coat Protein Shell is Likely Assembled Under Tension: A Novel Role for the MS2 Bacteriophage A Protein as Revealed by Small-angle Neutron Scattering

Kuzmanovic

Elashvili²,

Wick³

et al. 2006

Journal of Molecular Biology

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Section: Discussionmentioning

confidence: 97%

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confidence: 99%

The MS2 Coat Protein Shell is Likely Assembled Under Tension: A Novel Role for the MS2 Bacteriophage A Protein as Revealed by Small-angle Neutron Scattering

Kuzmanovic

Elashvili²,

Wick³

et al. 2006

Journal of Molecular Biology

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“…This value is about 50-fold higher than the association constant observed at optimum conditions. The reason for the rather slower rate than the diffusion-controlled rate is almost certainly the fact that MS2 phage has only a single reactive site, an A protein, interacting with F pilus [5,6]. Assuming that the orientation of the reactive site must lie within the appropriate solid angle to interact with the pilus and that the entire surface of the pilus is reactive, the association rate in the diffusion-controlled limid could be expressed by…”

Section: Discussionmentioning

confidence: 99%

“…Spherical RNA phages adsorb to F pilus in large numbers along the entire length of F pilus [1,2], while filamentous DNA phages adsorb to the tip of the pilus in limited numbers [3]. The binding of the RNA phage to the side of F pilus appears to be facilitated by the A protein component of the phage [5,6], and the isolation of a number of F pilus bacterial mutants with altered phage attachment properties [7-91 indicates that the adsorption process involves a highly specific protein -protein interactionThe interaction between the RNA phage and free F pilus has been studied by retention of the phagepilus complex on nitrocellulose filters [4,11,12]. There [lo].…”

mentioning

confidence: 99%

Kinetic Studies of the Interaction between MS2 Phage and F Pilus of Escherichia coli

Date

1979

European Journal of Biochemistry

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The kinetics of the binding reaction of MS2 phage to free F pili, which were highly purified from Escherichia coli, has been studied using a membrane filter assay. The rate of dissociation ( k d ) of the MS2-phage -F-pilus complex is very slow and follows first-order kinetics with a half-life of 4.2 h at 30°C in the standard buffer. The dissociation rate is rather insensitive to temperature, but becomes more rapid at high ionic strength or at basic pH. In a 0.25 M ionic strength buffer, the half-life of the complex is about 1 .O min. The rate of association is very fast and follows secondorder kinetics with the rate constant for association (ka) being 8 x lo7 M-' sC1 at 30 "C in the standard buffer. The rate of association is almost insensitive to ionic strength but slightly sensitive to pH or temperature. Monovalent cations can also promote the binding reaction as well as divalent cations but the complex formed with monovalent cation is unstable. A study of the kinetics of dissociation suggests that there are two types of interaction between MS2 phage and F pilus; one is a strong interaction formed with divalent cations and the other is a weak one formed with monovalent cations. The physical nature of the bonds involved in the former and the latter seems to be mainly electrostatic and non-electrostatic respectively. The mechanism of the binding reaction is discussed.Various types of molecules accessible from the bacterial envelope (protein, lipopolysaccharide, capsular polysaccharide, etc.) and appendages on the cell surface (flagella, sex pili) can serve as phage receptors. Adsorption of male-specific coliphage is attributed to F pilus [l -41, a class of sex pili which are a phenotypic expression of the fertility F factor [2]. Spherical RNA phages adsorb to F pilus in large numbers along the entire length of F pilus [1,2], while filamentous DNA phages adsorb to the tip of the pilus in limited numbers [3]. The binding of the RNA phage to the side of F pilus appears to be facilitated by the A protein component of the phage [5,6], and the isolation of a number of F pilus bacterial mutants with altered phage attachment properties [7-91 indicates that the adsorption process involves a highly specific protein -protein interactionThe interaction between the RNA phage and free F pilus has been studied by retention of the phagepilus complex on nitrocellulose filters [4,11,12]. There [lo].Ahhreviafions. kdr rate constant of dissociation; k,, rate constant of association; K , equilibrium constant ( k d / k a ) ; f l i 2 , dissociation half-life M-F complex, MS2-phage-F-pilus complex.Dqfinifion. Standard buffer, 10 mM Tris-HCI, pH 7.2, 5 mM CaCI2, and 20 pg/ml of streptomycin sulfate.is no specific requirement for the reaction and there is only a slight temperature dependence, the binding at 0 "C being about half that 37 "C 14,111. The binding reaction of the phage to F pilus is a reversible one [4], having an association constant of 1.75 at 4 "C when cell-bound F pili are used [13]. Very little is known, however, about t...

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“…The A-protein is in some way required for proper assembly since defective particles are formed during the growth of A-cistron amber mutants in non-permissive cells [4,5]. These defective particles contain originally an intact RNA-molecule, but which protrudes through the capsid and is accessible to nucleases present in the solvent [6,7]. Furthermore infective phage is only obtained in reconstitution experiments when A-protein is present [8] .…”

Section: Lntroduetionmentioning

confidence: 99%