Bacteriophage MS2: Difference between revisions
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| species = '''Bacteriophage MS2'''}} |
| species = '''Bacteriophage MS2'''}} |
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The '''bacteriophage MS2''' is an icosahedral, positive-sense single-stranded [[RNA]] virus that infects the bacterium [[Escherichia coli|''Escherichia coli'']].<ref name="van Duin">van Duin J, Tsareva N. Single-stranded RNA phages. Chapter 15 (pp. 175-196) in: Calendar RL (ed.), The Bacteriophages (Second Edition). Oxford University Press, 2006.</ref> |
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The '''bacteriophage MS2''' is an icosahedral bacteriophage<ref>Valegård, et al., The three-dimensional structure of the bacterial virus MS2, Nature, 345(6270):36-41, 1990</ref> with a diameter of 27-34 nm{{Citation needed|date=January 2010}} and an isoelectric point (pI) of 3.9<ref>Dowd, et al., Delineating the Specific Influence of Virus Isoelectric Point and Size on Virus Adsorption and Transport Through Sandy Soils, AEM, 64:2, 1998</ref>. MS2 phage can be propagated in ''Escherichia coli'', commonly ''E. coli'' [[American Type Culture Collection|ATCC]] 15597.{{Citation needed|date=January 2010}} |
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==History== |
==History== |
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In 1961, MS2 was isolated by Alvin John Clark and recognized as an RNA-containing phage very similar to [[bacteriophage f2]].<ref>Davis JE, Strauss JH, Sinsheimer RL. Bacteriophage MS2: another RNA phage. 1961 November 3; 134(3488):1427.</ref> |
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In [[1976]] the complete [[RNA]] sequence of Bacteriophage MS2 was determined, compared to the [[DNA]] sequence of the [[Phi-X174 phage]], which was determined by [[Fred Sanger]] and his team in [[1977]].<ref>Sanger, FF, et al. 1977. “Nucleotide sequence of bacteriophage phi X174 DNA.” Nature 265(5596): 687-95.</ref> These two genomes were the first to be determined in scientific history.{{Citation needed|date=January 2010}} |
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In [[1962]] it was established that the DNA of the phage Phi-X174 is in a ring-structure<ref>Fiers, W., and R. L. Sinsheimer, The structure of the DNA of bacteriophage PhiX 174. III. Ultracentrifuge evidence for a ring structure, J. Mol. Biol. 5:424-434, 1962</ref>. In [[1972]] a gene of Bacteriophage MS2 was the first gene of which the nucleotide sequence was known<ref>Min Jou W, Haegeman G, Ysebaert M, Fiers W., Nucleotide sequence of the gene coding for the bacteriophage MS2 coat protein, Nature. 1972 May 12;237(5350):82-8</ref><ref>Fiers W, Contreras R, Duerinck F, Haegmean G, Merregaert J, Jou WM, Raeymakers A, Volckaert G, Ysebaert M, Van de Kerckhove J, Nolf F, Van Montagu M., A-protein gene of bacteriophage MS2, Nature. 1975 July 24;256(5515):273-8</ref>. In [[1976]], it was the first complete genome to be sequenced, by [[Walter Fiers]] and his team at the [[University of Ghent]] ([[Ghent]], [[Belgium]])<ref>Fiers W, Contreras R, De Wachter R, Haegeman G, Merregaert J, Jou WM, Vandenberghe A., Recent progress in the sequence determination of bacteriophage MS2 RNA, Biochimie. 1971;53(4):495-506</ref><ref>Fiers W, Contreras R, Duerinck F, Haegeman G, Iserentant D, Merregaert J, Min Jou W, Molemans F, Raeymaekers A, Van den Berghe A, Volckaert G, Ysebaert M., Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene, Nature. 1976 April 8;260(5551):500-7.</ref>. |
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In 1976, MS2 was the first organism to have its genome completely sequenced.<ref name="Fiers">Fiers W, Contreras R, Duerinck F, Haegeman G, Iserentant D, Merregaert J, Min Jou W, Molemans F, Raeymaekers A, Van den Berghe A, Volckaert G, Ysebaert M., Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene, Nature. 1976 April 8;260(5551):500-7.</ref> This was accomplished by [[Walter Fiers]] and his team, building upon their earlier milestone in 1972 of the first gene to be completely sequenced, the MS2 coat protein.<ref>Min Jou W, Haegeman G, Ysebaert M, Fiers W., Nucleotide sequence of the gene coding for the bacteriophage MS2 coat protein, Nature. 1972 May 12;237(5350):82-8</ref> These sequences were determined at the RNA level, whereas the next landmark achievement, the sequence of the bacteriophage [[Phi X 174|ΦX174]] genome in 1977, was determined using DNA.<ref>Sanger, FF, et al. 1977. “Nucleotide sequence of bacteriophage phi X174 DNA.” Nature 265(5596): 687-95.</ref> |
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==Virology== |
==Virology== |
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This [[bacteriophage|phage]] has a very small genome which is 3,569 nucleotides long<ref>Fiers W, Contreras R, Duerinck F, Haegeman G, Iserentant D, Merregaert J, Min Jou W, Molemans F, Raeymaekers A, Van den Berghe A, Volckaert G, Ysebaert M., Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene, Nature. 1976 April 8;260(5551):500-7.</ref>. |
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The MS2 genome is one of the smallest known, 3569 nucleotides long.<ref name="Fiers" /> It encodes just four genes: the maturation protein (A-protein), the lysis protein, and the replicase protein.<ref name="van Duin" /> However, the expression of these proteins is regulated by complex interplay between [[Translation (biology)|translation]] and [[Nucleic acid secondary structure|RNA secondary structure]]. |
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An MS2 virion is about 27 nm in diameter (by electron microscopy).<ref>Strauss JH, Sinsheimer RL. Purification and properties of bacteriophage MS2 and of its ribonucleic acid. J Mol Biol. 1963 Jul;7:43-54</ref> It consists of one copy of the maturation protein and 180 copies of the coat protein (organized as 90 dimers) arranged into an icosahedral shell with triangulation number [[capsid#T-number|T=3]], protecting the genomic RNA inside.<ref>Valegård K, Lilias L, Fridborg K, Unge T. The three-dimensional structure of the bacterial virus MS2. Nature 1990 May 3;345(6270):36-41</ref> The virion has an [[isoelectric point]] (pI) of 3.9.<ref>Dowd, et al., Delineating the Specific Influence of Virus Isoelectric Point and Size on Virus Adsorption and Transport Through Sandy Soils, AEM, 64:2, 1998</ref> |
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MS2 infects only "male" ''E. coli'' bacteria, that is, those bearing an F [[pilus]]. It attaches to the side of the pilus via its single maturation protein. The precise mechanism by which phage RNA enters the bacterium is unknown. Once the RNA is inside, it begins to function as a [[messenger RNA]] for the production of phage proteins. The gene for the most abundant protein, the coat protein, can be immediately translated. The translation start of the replicase gene is normally hidden within RNA secondary structure, but can transiently opened as [[ribosome|ribosomes]] pass through the coat protein gene. Replicase translation is also shut down once large amounts of coat protein have been made; coat protein dimers bind and stabilize the RNA "operator [[stem-loop|hairpin]]", blocking the replicase start. The start of the maturation protein gene is accessible in RNA being replicated but hidden within RNA secondary structure in the completed MS2 RNA; this ensures translation of only a very few copies of maturation protein per RNA. Finally, the lysis protein gene can only be initiated by ribosomes that have completed translation of the coat protein gene and "slip back" to the start of the lysis protein gene, at about a 5% frequency.<ref name="van Duin" /> |
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Replication of the plus-strand MS2 genome requires synthesis of the complementary minus strand RNA, which can then be used as a template for synthesis of a new plus strand RNA. MS2 replication has been much less well studied than replication of the highly related [[bacteriophage Qβ]], partly because the MS2 replicase has been difficult to isolate, but is likely to be similar.<ref name="van Duin" /> |
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The formation of the virion is thought to be initiated by binding of maturation protein to the MS2 RNA; in fact, the complex of maturation protein and RNA is infectious. The assembly of the icosahedral shell or [[capsid]] from coat proteins can occur in the absence of RNA; however, capsid assembly is nucleated by coat protein dimer binding to the operator hairpin, and assembly occurs at much lower concentrations of coat protein when MS2 RNA is present.<ref name="van Duin" /> |
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Bacterial lysis and release of newly formed virions occurs when sufficient lysis protein has accumulated. Lysis protein forms pores in the cytoplasmic membrane, which leads to loss of [[membrane potential]] and breakdown of the [[cell wall#Bacterial cell walls|cell wall]].<ref name="van Duin" /> |
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==Notes== |
==Notes== |
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More recently, the MS2 operator hairpin and coat protein have found utility in the detection of RNA in living cells (see [[MS2 tagging]]). |
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More recently, small stem loops from the genome of the phage have found tremendous utility in the detection of RNA in living cells (see [[MS2 tagging]]). The high affinity, sequence-specific interaction between the stem loops and the coat protein serves as a means to direct [[Green fluorescent protein|GFP]] (via fusion to the coat protein) to the RNA. This has been used to image RNA localisation<ref>E. Bertrand, P. Chartrand, M. Schaefer, S.M. Shenoy, R.H. Singer and R.M. Long, Mol Cell 2 (1998) 437-45.</ref> and transcription itself <ref>Chubb, J. R., Trcek, T., Shenoy, S. M., and Singer, R. H. (2006b). Transcriptional pulsing of a developmental gene. Curr Biol 16, 1018-1025.</ref><ref>I. Golding, J. Paulsson, S.M. Zawilski and E.C. Cox, Cell 123 (2005) 1025-1036.</ref> (see [[transcriptional bursting]]). |
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==See also== |
==See also== |
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* [[bacteriophage f2]] |
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* [[bacteriophage Qβ]] |
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* [[Phi-X174 phage]] |
* [[Phi-X174 phage]] |
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* [[Bacteriophage]] |
* [[Bacteriophage]] |
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Revision as of 12:57, 25 October 2011
| Bacteriophage MS2 | |
|---|---|
| Virus classification | |
| Group: | Group IV ((+)ssRNA)
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| Family: | |
| Genus: | |
| Species: | Bacteriophage MS2
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The bacteriophage MS2 is an icosahedral, positive-sense single-stranded RNA virus that infects the bacterium Escherichia coli.[1]
History
In 1961, MS2 was isolated by Alvin John Clark and recognized as an RNA-containing phage very similar to bacteriophage f2.[2]
In 1976, MS2 was the first organism to have its genome completely sequenced.[3] This was accomplished by Walter Fiers and his team, building upon their earlier milestone in 1972 of the first gene to be completely sequenced, the MS2 coat protein.[4] These sequences were determined at the RNA level, whereas the next landmark achievement, the sequence of the bacteriophage ΦX174 genome in 1977, was determined using DNA.[5]
Virology
The MS2 genome is one of the smallest known, 3569 nucleotides long.[3] It encodes just four genes: the maturation protein (A-protein), the lysis protein, and the replicase protein.[1] However, the expression of these proteins is regulated by complex interplay between translation and RNA secondary structure.
An MS2 virion is about 27 nm in diameter (by electron microscopy).[6] It consists of one copy of the maturation protein and 180 copies of the coat protein (organized as 90 dimers) arranged into an icosahedral shell with triangulation number T=3, protecting the genomic RNA inside.[7] The virion has an isoelectric point (pI) of 3.9.[8]
MS2 infects only "male" E. coli bacteria, that is, those bearing an F pilus. It attaches to the side of the pilus via its single maturation protein. The precise mechanism by which phage RNA enters the bacterium is unknown. Once the RNA is inside, it begins to function as a messenger RNA for the production of phage proteins. The gene for the most abundant protein, the coat protein, can be immediately translated. The translation start of the replicase gene is normally hidden within RNA secondary structure, but can transiently opened as ribosomes pass through the coat protein gene. Replicase translation is also shut down once large amounts of coat protein have been made; coat protein dimers bind and stabilize the RNA "operator hairpin", blocking the replicase start. The start of the maturation protein gene is accessible in RNA being replicated but hidden within RNA secondary structure in the completed MS2 RNA; this ensures translation of only a very few copies of maturation protein per RNA. Finally, the lysis protein gene can only be initiated by ribosomes that have completed translation of the coat protein gene and "slip back" to the start of the lysis protein gene, at about a 5% frequency.[1]
Replication of the plus-strand MS2 genome requires synthesis of the complementary minus strand RNA, which can then be used as a template for synthesis of a new plus strand RNA. MS2 replication has been much less well studied than replication of the highly related bacteriophage Qβ, partly because the MS2 replicase has been difficult to isolate, but is likely to be similar.[1]
The formation of the virion is thought to be initiated by binding of maturation protein to the MS2 RNA; in fact, the complex of maturation protein and RNA is infectious. The assembly of the icosahedral shell or capsid from coat proteins can occur in the absence of RNA; however, capsid assembly is nucleated by coat protein dimer binding to the operator hairpin, and assembly occurs at much lower concentrations of coat protein when MS2 RNA is present.[1]
Bacterial lysis and release of newly formed virions occurs when sufficient lysis protein has accumulated. Lysis protein forms pores in the cytoplasmic membrane, which leads to loss of membrane potential and breakdown of the cell wall.[1]
Notes
More recently, the MS2 operator hairpin and coat protein have found utility in the detection of RNA in living cells (see MS2 tagging).
See also
External links
- Complete genome (also isolates R17, DL16, and J20)
References
- ^ a b c d e f van Duin J, Tsareva N. Single-stranded RNA phages. Chapter 15 (pp. 175-196) in: Calendar RL (ed.), The Bacteriophages (Second Edition). Oxford University Press, 2006.
- ^ Davis JE, Strauss JH, Sinsheimer RL. Bacteriophage MS2: another RNA phage. 1961 November 3; 134(3488):1427.
- ^ a b Fiers W, Contreras R, Duerinck F, Haegeman G, Iserentant D, Merregaert J, Min Jou W, Molemans F, Raeymaekers A, Van den Berghe A, Volckaert G, Ysebaert M., Complete nucleotide sequence of bacteriophage MS2 RNA: primary and secondary structure of the replicase gene, Nature. 1976 April 8;260(5551):500-7.
- ^ Min Jou W, Haegeman G, Ysebaert M, Fiers W., Nucleotide sequence of the gene coding for the bacteriophage MS2 coat protein, Nature. 1972 May 12;237(5350):82-8
- ^ Sanger, FF, et al. 1977. “Nucleotide sequence of bacteriophage phi X174 DNA.” Nature 265(5596): 687-95.
- ^ Strauss JH, Sinsheimer RL. Purification and properties of bacteriophage MS2 and of its ribonucleic acid. J Mol Biol. 1963 Jul;7:43-54
- ^ Valegård K, Lilias L, Fridborg K, Unge T. The three-dimensional structure of the bacterial virus MS2. Nature 1990 May 3;345(6270):36-41
- ^ Dowd, et al., Delineating the Specific Influence of Virus Isoelectric Point and Size on Virus Adsorption and Transport Through Sandy Soils, AEM, 64:2, 1998