For a number of years, we have been pursuing two lines of research, both involving nucleic acids as well as proteins. Like many other enveloped viruses, retroviruses are formed under the plasma membrane of the infected cell, emerging by budding - i.e. wrapping themselves in a piece of membrane derived from the host cell.
Cleavage leads to morphological and biochemical changes in the virus particle.
We are interested in a number of questions that relate to assembly and maturation. Some of these introns can transpose specifically, as DNA elements, to an unoccupied site in a homologous gene that does not carry the intron. The endonuclease cleaves the target site, thus initiating a gene conversion event, by which the intron-containing DNA sequences are copied into the DNA that has been broken. Most group I introns exist in the DNA of mitochondria or chloroplasts. We have been studying the three known examples of mobile introns in the nucleus.