Search results
Results from the WOW.Com Content Network
Lambda phage is a non-contractile tailed phage, meaning during an infection event it cannot 'force' its DNA through a bacterial cell membrane. It must instead use an existing pathway to invade the host cell, having evolved the tip of its tail to interact with a specific pore to allow entry of its DNA to the hosts.
A cosmid is a type of hybrid plasmid that contains a Lambda phage cos sequence. [1] Often used as cloning vectors in genetic engineering, cosmids can be used to build genomic libraries. They were first described by Collins and Hohn in 1978. [2] Cosmids can contain 37 to 52 (normally 45) kb of DNA, limits based on the normal bacteriophage ...
Phages like the lambda phage use their site specific recombinases to integrate their DNA into the host genome during lysogeny. P1 phage DNA on the other hand, exists as a plasmid in the host. The Cre-lox system serves several functions in the phage: it circularizes the phage DNA into a plasmid, separates interlinked plasmid rings so they are ...
Temperate phages (such as lambda phage) can reproduce using both the lytic and the lysogenic cycle. [4] How a phage decides which cycle to enter depends on a variety of factors. [5] For instance, if there are several other infecting phages (or if there is a high multiplicity), it is likely that the phage will use the lysogenic cycle.
The earliest identified members of the serine recombinase family were known as resolvases or DNA invertases, while the founding member of the tyrosine recombinases, lambda phage integrase (using attP/B recognition sites), differs from the now well-known enzymes such as Cre (from the P1 phage) and FLP (from the yeast Saccharomyces cerevisiae).
cII is the central “switchman” in the lambda phage bistable genetic switch, allowing environmental and cellular conditions to factor into the decision to lysogenize or to lyse its host. [ 4 ] cII acts as a transcriptional activator of three promoters on the phage genome : pI, pRE, and pAQ.
Bacteriophage lambda encodes two repressors: the Cro repressor that acts to turn off early gene transcription during the lytic cycle, and the lambda or cI repressor required to maintain lysogenic growth. Together the Cro and cI repressors form a helix-turn-helix (HTH) superfamily. The lambda Cro repressor binds to DNA as a highly flexible dimer.
A concatemer is a long continuous DNA molecule that contains multiple copies of the same DNA sequence linked in series. These polymeric molecules are usually copies of an entire genome linked end to end and separated by cos sites (a protein binding nucleotide sequence that occurs once in each copy of the genome).