000			01627 am a22002053u 4500
042			_adc
100	1	0	_aLiao, Chunyu _eauthor _92430
700	1	0	_aBeisel, Chase L. _eauthor _92431
245	0	0	_aThe tracrRNA in CRISPR biology and technologies
260			_c2021-11-23.
500			_a/pmc/articles/PMC7614092/
500			_a/pubmed/34416117
520			_aCRISPR-Cas adaptive immune systems in bacteria and archaea utilize short CRISPR RNAs (crRNAs) to guide sequence-specific recognition and clearance of foreign genetic material. Multiple crRNAs are stored together in a compact format called a CRISPR array that is transcribed and processed into the individual crRNAs. While the exact processing mechanisms vary widely, some CRISPR-Cas systems including those encoding the Cas9 nuclease rely on a trans-activating crRNA (tracrRNA). The tracrRNA was discovered in 2011 and was quickly co-opted to create single-guide RNAs as core components of CRISPR-Cas9 technologies. Since then, further studies have uncovered processes extending beyond the tracrRNA's traditional role in crRNA biogenesis, revealed Cas nucleases besides Cas9 that are dependent on tracrRNAs, and established new applications based on tracrRNA engineering. In this review, we describe the biology of the tracrRNA and how its ongoing characterization has garnered new insights into prokaryotic immune defense and enabled key technological advances.
540			_a
546			_aen
690			_aArticle
655	7		_aText _2local
786	0		_nAnnu Rev Genet
856	4	1	_uhttp://dx.doi.org/10.1146/annurev-genet-071719-022559 _zConnect to this object online.
999			_c915 _d915