BIOL2202 Lecture Notes - Lecture 11: Transposable Element, Transposase, Reverse Transcriptase
Document Summary
Cut-and-paste transpositions: the dna element is excised from one site and pasted into another site, transposase enzyme is encoded within the transposon and performs this function. Replicative transpositions: the dna element is first replicated, the replicated segment is pasted into another site, the original dna element is not excised. Bacterial transposons: bacteria only have cut-and-past transposons and replicative transposons, some specific types of bacterial transposons: Insertion sequence elements (is elements) cut and paste: composite transposons cut and paste, tn3 elements replicative transposons. This can be a random area in the gene. Or it can be a specific site (eg: some transposase cut anywhere with an at sequence) Where are is elements found: bacterial chromosome and plasmids contain many types of is elements, each with many copies. If a specific is element is on both a plasmid and a chromosome, homologous recombination can happen.
