Uploaded November 2016 | Updated September 2026, 1 day ago
In molecular biology, RNA splicing is the editing of the nascent pre-messenger RNA (pre-mRNA) transcript. After splicing, introns are removed and exons are joined together (ligated). For nuclear-encoded genes, splicing takes place within the nucleus either co-transcriptionally or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein. For many eukaryotic introns, splicing is carried out in a series of reactions which are catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins (snRNPs). Self-splicing introns, or ribozymes capable of catalyzing their own excision from their parent RNA molecule, also exist.
Self-splicing occurs for rare introns that form a ribozyme, performing the functions of the spliceosome by RNA alone. There are three kinds of self-splicing introns, Group I, Group II and Group III. Group I and II introns perform splicing similar to the spliceosome without requiring any protein. This similarity suggests that Group I and II introns may be evolutionarily related to the spliceosome. Self-splicing may also be very ancient, and may have existed in an RNA world present before protein.
Two transesterifications characterize the mechanism in which group I introns are spliced:
3'OH of a free guanine nucleoside (or one located in the intron) or a nucleotide cofactor (GMP, GDP, GTP) attacks phosphate at the 5' splice site.
3'OH of the 5' exon becomes a nucleophile and the second transesterification results in the joining of the two exons.
The mechanism in which group II introns are spliced (two transesterification reaction like group I introns) is as follows:
The 3'OH of a specific adenosine in the intron attacks the 5' splice site, thereby forming the lariat
The 3'OH of the 5' exon triggers the second transesterification at the 3' splice site, thereby joining the exons together.
Thank You for watching our videos from Biology Animation Videos channel. This channel is created to compile animated biology lectures and videos from different animation sources. None of these videos are created by us. we just organize them and place them in YouTube for your understanding so If you want to know details about these animation please see the credit section for knowing the original content developer and please convey privilege and gratitude to them. Thank You.
Our website-
biologyanimationvideos.weebly.com
Thank you for watching RNA splicing animation.
In molecular biology, RNA splicing is the editing of the nascent pre-messenger RNA (pre-mRNA) transcript. After splicing, introns are removed and exons are joined together (ligated). For nuclear-encoded genes, splicing takes place within the nucleus either co-transcriptionally or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein. For many eukaryotic introns, splicing is carried out in a series of reactions which are catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins (snRNPs). Self-splicing introns, or ribozymes capable of catalyzing their own excision from their parent RNA molecule, also exist.
Self-splicing occurs for rare introns that form a ribozyme, performing the functions of the spliceosome by RNA alone. There are three kinds of self-splicing introns, Group I, Group II and Group III. Group I and II introns perform splicing similar to the spliceosome without requiring any protein. This similarity suggests that Group I and II introns may be evolutionarily related to the spliceosome. Self-splicing may also be very ancient, and may have existed in an RNA world present before protein.
Two transesterifications characterize the mechanism in which group I introns are spliced:
3'OH of a free guanine nucleoside (or one located in the intron) or a nucleotide cofactor (GMP, GDP, GTP) attacks phosphate at the 5' splice site.
3'OH of the 5' exon becomes a nucleophile and the second transesterification results in the joining of the two exons.
The mechanism in which group II introns are spliced (two transesterification reaction like group I introns) is as follows:
The 3'OH of a specific adenosine in the intron attacks the 5' splice site, thereby forming the lariat
The 3'OH of the 5' exon triggers the second transesterification at the 3' splice site, thereby joining the exons together.
Thank You for watching our videos from Biology Animation Videos channel. This channel is created to compile animated biology lectures and videos from different animation sources. None of these videos are created by us. we just organize them and place them in YouTube for your understanding so If you want to know details about these animation please see the credit section for knowing the original content developer and please convey privilege and gratitude to them. Thank You.
Our website-
biologyanimationvideos.weebly.com
Thank you for watching RNA splicing animation.
