Bacteriophage lambda - Revision history

Saleksander: Redirected page to Phage lambda

2011-08-04T19:24:53Z

Redirected page to Phage lambda

← Older revision		Revision as of 19:24, 4 August 2011
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	~~Bacteriophage λ is the archetype of the~~ [[Lambdoid phage\|lambdoid]], or lambda-like phage, a subclass of the [http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/02.066.htm siphoviridae]. λ is a temperate phage. The λ strain used most often in labs, although called wt, is λ''PaPa'', named after the parental strains from '''Pa'''sedena California and the Institut Pasteur in '''Pa'''ris. <ref name='PMID:1439823'/>		#REDIRECT [[Phage_lambda]]

	~~== Morphology ==~~
	The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is formed from the proteins E, D, B, W, FII, B*, X1, and X2. <ref name="Basic Virology"> Edward K. Wagner et al (2007) Basic Virology (Wiley-Blackwell) ISBN 978-1-4051-4715-6</ref> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes using host ligase at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host.<ref name='LIB:Lambda_II'/> <ref name="Basic Virology"/> The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>

	~~== Genome Organization ==~~

	~~== Life Cycle ==~~
	~~=== Lytic Cycle ===~~
	~~The lytic cycle is the usual life cycle, and results in the death of the host bacteria.~~

	~~==== Adsorbtion and Injection ====~~
	The tip of the phage tail ([[Phage_lambda_J:Gene_Product(s)\|J protein]]) attaches to the host cell protein [[lamB]], which is displayed on the outer membrane.<ref name='LIB:Lambda_II'/> The dsDNA is injected through the tail as a linear genome, when the phage tail interacts with the inner membrane protein [[ptsM]] and recircularizes once inside the host due to complementary 12nt long sticky ends. <ref name='LIB:Lambda_II'/>

	~~==== Early Gene Expression ====~~
	~~The cro gene produces an immediate-early gene product.<ref name='LIB:BofV'/>~~
	~~CII and CIII are delayed-early gene products. <ref name='LIB:BofV'/>~~
	~~==== Middle Gene Expression ====~~

	~~==== DNA Replication ====~~
	Replication directly after injection proceeds via θ (theta) replication after host gyrase supercoils the λ DNA. <ref name="Basic Virology"/> Replication proceeds via rolling circle replication when entering the lytic cycle, aided by phage-encoded endonuclease which cuts the (+) strand.<ref name="Basic Virology"/>

	~~==== Late Gene Expression ====~~

	~~==== Packaging ====~~
	~~The DNA replicated by rolling circle remains as concatomers until terminase cleaves the '''cos''' site and one end of the DNA is packed into the capsid.<ref name="Basic Virology"/>~~
	Proteins B, C, and Nu3 form the capsid precursors, which are aided by host [[groEL]] and [[groES]] to combine with E to form an immature capsid. <ref name="Basic Virology"/> The proteins E and C combined and are reformed into X1 and X2, which make a mature capsid once B* is added (from B) and Nu3 is degraded. <ref name="Basic Virology"/>

	D protein is added to the capsid, and the λ DNA is inserted until the terminase cuts the DNA at the next '''cos''' site, then W and FII proteins stabilize the capsid.<ref name="Basic Virology"/>

	~~Tails are formed seperately from the far end of the structure in the proteins in the order J, I, L, K, H, G, M, V, U, H, and Z~~
	~~and attach spontaneously to mature capsids by proteins W and FII.<ref name="Basic Virology"/>~~

	~~==== Lysis ====~~
	Proteins R and S are used to degrade the bacterial membranes, with S acting on the inner and R on the outer membrane. <ref name="Basic Virology"/> About 100 phage are released per host, and infection to release takes about 35 minutes. <ref name="Basic Virology"/>

	~~=== Lysogenic State ===~~
	The lysogenic lifecycle is the result of integration of the λ DNA into the host genome, and does not result in the death of the host cell. The λ DNA/host DNA unit is termed a prophage, and decendants of the prophage are capable of producing phage when the λ DNA excises from the host DNA. <ref name='PMID:17247494'/>
	~~The λ DNA is integrated at the ''att''P (for '''att'''achment '''p'''hage) and the ''att''B (for '''att'''achment '''b'''acteria) loci.<ref name='LIB:BofV'/>~~

	~~=== Lysis-Lysogeny Switch ===~~

	~~=== Prophage Induction ===~~


	~~== See also ==~~
	*[[:Category:Gene_List:Phage_lambda~~\|Lambda Gene List]]~~
	*[http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=10710&lvl=3&lin=f&keep=1&srchmode=1&unlock Enterobacteriophage lambda at the NCBI taxonomy browser]
	*[[wikipedia: Lambda_phage]]
	*[http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/02.066.0.01.001.htm ICTVdb entry]
	*[http://microbewiki.kenyon.edu/index.php/Siphoviridae Siphoviridae at MicrobeWiki]
	*[http://www.uniprot.org/taxonomy/10710 Phage lambda on UniProt]

	~~== References ==~~
	~~{{RefHelp}}~~
	~~<references/>~~

	~~[[Category:lambda-like~~]]

Saleksander: /* Lysis */

2011-08-03T21:24:44Z

Lysis

← Older revision		Revision as of 21:24, 3 August 2011
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	==== Lysis ====		==== Lysis ====
			Proteins R and S are used to degrade the bacterial membranes, with S acting on the inner and R on the outer membrane. <ref name="Basic Virology"/> About 100 phage are released per host, and infection to release takes about 35 minutes. <ref name="Basic Virology"/>

	=== Lysogenic State ===		=== Lysogenic State ===

Saleksander: /* Packaging */

2011-08-03T21:17:17Z

Packaging

← Older revision		Revision as of 21:17, 3 August 2011
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	==== Packaging ====		==== Packaging ====
	The DNA replicated by rolling circle remains as concatomers until terminase cleaves the '''cos''' site and one end of the DNA is packed into the capsid.<ref name="Basic Virology"/>		The DNA replicated by rolling circle remains as concatomers until terminase cleaves the '''cos''' site and one end of the DNA is packed into the capsid.<ref name="Basic Virology"/>
	Proteins B, C, and Nu3 form the capsid precursors, which are aided by host [[groEL]] and [[groES]] to combine with E to form an immature capsid. <ref name="Basic Virology"/> The ~~λ DNA is inserted~~ into ~~the~~ capsid ~~until the terminase cuts the DNA at the next '''cos''' site, then W~~ and ~~FII proteins stabilize the capsid~~.<ref name="Basic Virology"/>		Proteins B, C, and Nu3 form the capsid precursors, which are aided by host [[groEL]] and [[groES]] to combine with E to form an immature capsid. <ref name="Basic Virology"/> The proteins E and C combined and are reformed into X1 and X2, which make a mature capsid once B* is added (from B) and Nu3 is degraded. <ref name="Basic Virology"/>

	Tails are formed seperately from the proteins		D protein is added to the capsid, and the λ DNA is inserted until the terminase cuts the DNA at the next '''cos''' site, then W and FII proteins stabilize the capsid.<ref name="Basic Virology"/>
	and attach spontaneously to mature capsids.
			Tails are formed seperately from the far end of the structure in the proteins in the order J, I, L, K, H, G, M, V, U, H, and Z
			and attach spontaneously to mature capsids by proteins W and FII.<ref name="Basic Virology"/>

	==== Lysis ====		==== Lysis ====

Saleksander: /* Packaging */

2011-08-03T21:06:19Z

Packaging

← Older revision		Revision as of 21:06, 3 August 2011
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	==== Packaging ====		==== Packaging ====
	The DNA replicated by rolling circle remains as concatomers until terminase cleaves the '''cos''' site and one end of the DNA is packed into the capsid.<ref name="Basic Virology"/> The λ DNA is inserted into the capsid until the terminase cuts the DNA at the next '''cos''' site, then W and FII proteins stabilize the capsid.<ref name="Basic Virology"/>		The DNA replicated by rolling circle remains as concatomers until terminase cleaves the '''cos''' site and one end of the DNA is packed into the capsid.<ref name="Basic Virology"/>
			Proteins B, C, and Nu3 form the capsid precursors, which are aided by host [[groEL]] and [[groES]] to combine with E to form an immature capsid. <ref name="Basic Virology"/> The λ DNA is inserted into the capsid until the terminase cuts the DNA at the next '''cos''' site, then W and FII proteins stabilize the capsid.<ref name="Basic Virology"/>

			Tails are formed seperately from the proteins
			and attach spontaneously to mature capsids.

	==== Lysis ====		==== Lysis ====

Saleksander: /* Packaging */

2011-08-03T20:59:01Z

Packaging

← Older revision		Revision as of 20:59, 3 August 2011
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	==== Packaging ====		==== Packaging ====
			The DNA replicated by rolling circle remains as concatomers until terminase cleaves the '''cos''' site and one end of the DNA is packed into the capsid.<ref name="Basic Virology"/> The λ DNA is inserted into the capsid until the terminase cuts the DNA at the next '''cos''' site, then W and FII proteins stabilize the capsid.<ref name="Basic Virology"/>

	==== Lysis ====		==== Lysis ====

Saleksander: /* DNA Replication */

2011-08-03T20:50:00Z

DNA Replication

← Older revision		Revision as of 20:50, 3 August 2011
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	==== DNA Replication ====		==== DNA Replication ====
	Replication proceeds via θ (theta) replication after host gyrase supercoils the λ DNA. <ref name="Basic Virology"/>		Replication directly after injection proceeds via θ (theta) replication after host gyrase supercoils the λ DNA. <ref name="Basic Virology"/> Replication proceeds via rolling circle replication when entering the lytic cycle, aided by phage-encoded endonuclease which cuts the (+) strand.<ref name="Basic Virology"/>

	==== Late Gene Expression ====		==== Late Gene Expression ====

Saleksander: /* DNA Replication */

2011-08-03T20:45:02Z

DNA Replication

← Older revision		Revision as of 20:45, 3 August 2011
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	==== DNA Replication ====		==== DNA Replication ====
			Replication proceeds via θ (theta) replication after host gyrase supercoils the λ DNA. <ref name="Basic Virology"/>

	==== Late Gene Expression ====		==== Late Gene Expression ====

Saleksander: /* Morphology */

2011-08-03T20:42:03Z

Morphology

← Older revision		Revision as of 20:42, 3 August 2011
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	== Morphology ==		== Morphology ==
	The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is formed from the proteins E, D, B, W, FII, B*, X1, and X2. <ref name="Basic Virology"> Edward K. Wagner et al (2007) Basic Virology (Wiley-Blackwell) ISBN 978-1-4051-4715-6</ref> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host~~, using host ligase~~.<ref name='LIB:Lambda_II'/> <ref name="Basic Virology"/> The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>		The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is formed from the proteins E, D, B, W, FII, B*, X1, and X2. <ref name="Basic Virology"> Edward K. Wagner et al (2007) Basic Virology (Wiley-Blackwell) ISBN 978-1-4051-4715-6</ref> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes using host ligase at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host.<ref name='LIB:Lambda_II'/> <ref name="Basic Virology"/> The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>

	== Genome Organization ==		== Genome Organization ==

Saleksander at 20:40, 3 August 2011

2011-08-03T20:40:17Z

← Older revision		Revision as of 20:40, 3 August 2011
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	== Morphology ==		== Morphology ==
	The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host. <ref name='LIB:Lambda_II'/> ~~The capsid is formed from the proteins E, D, B, W, FII, B*, X1, and X2.~~ <ref name="Basic Virology"~~> Edward K. Wagner et al (2007) Basic Virology (Wiley-Blackwell) ISBN 978-1-4051-4715-6<~~/~~ref~~> The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>		The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is formed from the proteins E, D, B, W, FII, B*, X1, and X2. <ref name="Basic Virology"> Edward K. Wagner et al (2007) Basic Virology (Wiley-Blackwell) ISBN 978-1-4051-4715-6</ref> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host, using host ligase.<ref name='LIB:Lambda_II'/> <ref name="Basic Virology"/> The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>

	== Genome Organization ==		== Genome Organization ==

Saleksander at 20:38, 3 August 2011

2011-08-03T20:38:19Z

← Older revision		Revision as of 20:38, 3 August 2011
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	== Morphology ==		== Morphology ==
	The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host. <ref name='LIB:Lambda_II'/> The capsid is formed from the proteins E, D, B, W, FII, B*, X1, and X2		The λ phage has an icosahedral head about 50 nm in diameter, and a flexible, noncontractile tail about 150nm long.<ref name='LIB:Lambda_II'/><ref name='PMID:1439823'/> The head is the capsid, and contains a single double-stranded DNA molecule about 48 kb in length; by weight the genome is about 32x10<sup>6</sup> Da and comprises about half of the phage's weight.<ref name='LIB:Lambda_II'/> The DNA is linear when packaged, and recircularizes at the ''cos'' ('''co'''hesive end '''s'''ite) once injected into the host. <ref name='LIB:Lambda_II'/> The capsid is formed from the proteins E, D, B, W, FII, B*, X1, and X2. <ref name="Basic Virology"> Edward K. Wagner et al (2007) Basic Virology (Wiley-Blackwell) ISBN 978-1-4051-4715-6</ref> The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>


	The wt λ does not have tail fibers, although these may be present on certain strains.<ref name='PMID:1439823'/>

	== Genome Organization ==		== Genome Organization ==