In this article, we are going to explore the fascinating world of Trans-activating crRNA. From its impact on today's society to its relevance in history, Trans-activating crRNA has captivated the attention of many people over the years. Through detailed analysis, we will examine the different facets of Trans-activating crRNA, unraveling its mysteries and discovering its true meaning. With a critical and objective perspective, we will immerse ourselves in the multiple dimensions of Trans-activating crRNA, seeking to understand its importance and influence in various spheres of life. So get ready for an exciting journey as we delve deeper into the topic of Trans-activating crRNA and discover everything it has to offer.
In molecular biology, trans-activating CRISPR RNA (tracrRNA) is a small trans-encoded RNA. It was first discovered by Emmanuelle Charpentier in her study of the human pathogen Streptococcus pyogenes.[1] In bacteria and archaea, CRISPR-Cas (clustered, regularly interspaced short palindromic repeats/CRISPR-associated proteins) constitute an RNA-mediated defense system that protects against viruses and plasmids. This defensive pathway has three steps. First, a copy of the invading nucleic acid is integrated into the CRISPR locus. Next, CRISPR RNAs (crRNAs) are transcribed from this CRISPR locus. The crRNAs are then incorporated into effector complexes, where the crRNA guides the complex to the invading nucleic acid and the Cas proteins degrade this nucleic acid.[2] There are several CRISPR system subtypes.
Type II CRISPR-Cas systems require a tracrRNA which plays a role in the maturation of crRNA.[3] The tracrRNA is partially complementary to and base pairs with a pre-crRNA forming an RNA duplex. This is cleaved by RNase III, an RNA-specific ribonuclease, to form a crRNA/tracrRNA hybrid. This hybrid acts as a guide for the endonuclease Cas9, which cleaves the invading nucleic acid.[1][4][5]