MCB 250 Lecture Notes - Lecture 24: Transposable Element, Reverse Transcriptase, Dna Replication

• School: University of Illinois
• Department: Molecular and Cell Biology
• Course: MCB 250
• Professor: J Slauch

Document Summary

Unlike viruses, the transposon cannot form a protein- or membrane-bound particle. It is also unable to lyse the host cell to escape: transposons are diverse. Transposition: transposons relocate using a distinctive form of recombination known as transposition. Dna: the exact mechanism by which transposase excises the transposon dna varies for different classes of transposons. The host cell can repair this dsb using either homologous recombination or non-homologous end joining. Insertion: following excision, the transposon dna (plus the transposase enzyme, not shown here) inserts into a target site elsewhere in the host cell"s dna. These two cleavages are staggered, and therefore produce 5" overhangs. A dna transposon that lacks a functional transposase gene can still undergo transposition by relying upon the transposase synthesized by a second transposon within the same cell. Although they are not living cells, transposons have played many important roles in the evolution of life on.