Difference between revisions of "Part:BBa K1906005"

Revision as of 15:45, 19 October 2016

Beta-subunit of Qbeta replicase holoenzyme

Multifunctional protein that promotes group II intron splicing and mobility by acting both on RNA and DNA. It has three activities: reverse transcriptase (RT) for intron duplication, maturase to promote splicing, and DNA endonuclease for site-specific cleavage of recipient alleles. The intron-encoded protein promotes splicing by facilitating the formation of the catalytically active structure of the intron RNA. After splicing, the protein remains bound to the excised intron lariat RNA, forming ribonucleoprotein particles, and cleaving the antisense strand of the recipient DNA in the 3' exon. After DNA cleavage, retrohoming occurs by a target DNA-primed reverse transcription of the intron RNA that had reverse spliced into the sense strand of the recipient DNA. It also contributes to the recognition of the DNA target site and acts as a repressor of its own translation.