Which of the Following is True Regarding Retroviral-Like Retrotransposons

Question

Which of the following is true regarding retroviral-like retrotransposons?
A) They encode both a reverse transcriptase and an RNA polymerase.
B) They have directly repeated long terminal repeats at their two ends when integrated into chromosomal DNA.
C) Their genomic RNA can be translated to produce viral coat proteins.
D) They leave double-strand breaks in the original donor DNA.
E) The Alu element in our genome is an example of retroviral-like retrotransposons.

Accepted Answer

Retroviral-like retrotransposons resemble retroviruses in their replication, but lack the ability to produce a protein coat. They have directly repeated long terminal repeats at each end and are transcribed by cellular RNA polymerases. The transcript is then used as a template by a reverse transcriptase (encoded by the element) to make a double-stranded DNA copy that is then integrated into a new site on the chromosome using an integrase (also encoded by the element). This mechanism keeps the original copy unchanged. Alu elements are nonretroviral retrotransposons.