|
|
| (19 intermediate revisions by the same user not shown) |
| Line 1: |
Line 1: |
| 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.
| | #REDIRECT [[Phage_lambda]] |
| | |
| == Morphology ==
| |
| The λ phage has an icosahedral head about 50 nm in diameter, and a flexible tail about 150nm long.<ref name='LIB:Lambda_II'/> The head 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'/>
| |
| == 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 is 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 ====
| |
| | |
| | |
| ==== Late Gene Expression ====
| |
| | |
| ==== Packaging ====
| |
| | |
| ==== Lysis ====
| |
| | |
| === 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.
| |
| The lysogenic state is the
| |
| === Lysis-Lysogeny Switch ===
| |
| | |
| === Prophage Induction ===
| |
| | |
| | |
| == See also ==
| |
| *[http://ecoliwiki.net/colipedia/index.php/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]]
| |