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    RNA, traditionally known for its role in gene expression and protein synthesis, has emerged as a remarkable molecule with catalytic properties. RNA catalysis, also known as ribozymes, challenges the dogma that catalysis is exclusive to protein enzymes.

     In the production of proteins, there are three primary kinds of RNA. They are Ribosomal RNA(rRNA), Messenger RNA(mRNA), and Transfer RNA(tRNA).

    The genetic code needed to generate proteins is found in mRNA, which is produced from DNA. In eukaryotes, a newly generated RNA transcript is referred to as a pre-mRNA and needs to go through maturation to become an mRNA. Introns and exons, which are referred to as coding and non-coding sections, respectively, are found in pre-mRNA. The exons are linked together and the introns are spliced during the processing of pre-mRNA. The 5' end of the RNA transcript receives a 5' cap called 7-methylguanosine, while the 3' end is polyadenylated.

    RNA catalysis refers to the ability of RNA molecules to accelerate chemical reactions by serving as enzymatic catalysts. This discovery shattered the notion that catalysis was solely the domain of proteins. Ribozymes are RNA molecules with specific threedimensional structures that enable them to bind to and modify target molecules. Their catalytic activities are driven by a combination of base pairing, tertiary interactions, and metal ion coordination.

    There are different mechanisms by which RNA molecules can catalyze reactions. The most well-known mechanism is the cleavage of RNA itself, catalyzed by ribozymes called self-cleaving ribozymes. These ribozymes can cleave specific phosphodiester bonds within their own RNA sequence, resulting in two separate RNA fragments.

    Another mechanism involves RNA acting as an enzyme in a manner similar to protein enzymes. For example, the hammerhead ribozyme exhibits a typical enzyme-substrate interaction, where the ribozyme binds to a specific RNA substrate and facilitates its cleavage. Similarly, the hairpin ribozyme can cleave RNA by bringing two distant regions into close proximity.

    RNA catalysis possesses several unique features. First, RNA molecules can undergo structural changes upon binding to specific substrates, which allows for selective catalytic activity. Second, RNA catalysis can occur under a wide range of conditions, including high temperatures and extreme pH levels. This robustness makes ribozymes attractive for biotechnological applications. 

    The discovery and understanding of RNA catalysis have opened up exciting possibilities in various fields. One of the significant applications is in the development of therapeutic agents. Ribozymes can be engineered to target and cleave disease-causing RNA molecules, potentially offering new treatments for genetic disorders and viral infections.  

    Moreover, RNA catalysis has implications in the field of synthetic biology. Researchers are exploring ways to design and engineer novel ribozymes to carry out specific chemical reactions, which could revolutionize the production of pharmaceuticals, biofuels, and other valuable compounds.

    RNA catalysis has transformed the understanding of the molecular world by highlighting the catalytic potential of RNA molecules. As research in this field progresses, it can be expected unlock even more diverse and powerful applications, ultimately leading to significant advancements in medicine, biotechnology, and chemical synthesis.  

文章節錄自：

Li, M. Z.(2023)。Catalytic RNA: RNA's Role as Catalysts in Biological Reactions。 Global Journal of Life Science and Biological Research,9(2)。 https://www.longdom.org/articles/catalytic-rna-rnas-role-as-catalysts-in-biologicalreactions-101918.html 

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