Transcript the element makes na RNA copy of itself which is reversed

Replicação na presença de erros
Recombination at the Molecular Level
• Breakage and joining also directed by enzymes.
• Homologous recombination occurs during synapsis in
meiosis I, general recombination in bacteria, and viral
genetic exchange.
• Molecular mechanism proposed by Holliday and
Whitehouse (1964).
• Depends on complementary base pairing.
RecA protein-mediated DNA synapsis
Rec A has multiple DNA binding sites, hence can
hold a single strand and a double helix together
Rec A is also a DNA-dependent ATPase
Recombinational
DNA
repair
Site-specific
recombination
Integração ou excisão de um bacteriofago
Conservative transposition – the element itself moves from the donor site into the target site
Replicative transposition – the element moves a copy of itself to a new site via a DNA intermediate
Retrotransposition – the element makes na RNA copy of itself which is reversed transcribed
into a DNA which is then inserted
When IS elements get it together:
composite transposons
Tn10 (E.coli)
Two IS elements flank an antibiotic resistance gene