RNA ligases are enzymes that facilitate the joining of two RNA molecules by forming a covalent bond between them. This process is essential for various biological functions, including the maturation of tRNA and the processing of mRNA. RNA ligases can also be used in laboratory settings for RNA manipulation and synthesis. These enzymes work by catalyzing the reaction that links the 3' hydroxyl group of one RNA strand to the 5' phosphate group of another. This action creates a continuous RNA strand, which is crucial for the stability and functionality of RNA in cellular processes.