Self-splicing refers to the process in which a segment of RNA removes itself from a larger RNA molecule without the assistance of proteins or enzymes. Self-splicing happens when introns acting as ribozymes catalyze their own removal from the mature RNA molecule. The RNA molecule folds into a specific three-dimensional structure, allowing it to catalyze its own removal from the primary RNA transcript. This process also involves the regulation of nucleotide interactions within the intron. It is important to note that self-splicing enzymes are not defined as enzymes. After self-splicing, the pre-RNA molecule transforms into mature RNA, which does not contain the intron and the freed intron itself. Consequently, each intron is only capable of splicing one time.