Small nuclear RNA
Further, the molar nuclear RNA known as U-RNA is the (snRNA), which is a class of small RNA molecules present in the nucleus of eukaryotic cells. the average length of the snRNA is 150 nucleotides degree. These are sent from RNA polymerase III or RNA polymerase II, in the process of (hnRNA) pre-m RNA in the nucleus, research has demonstrated that its main function. They, RNA polymerase II regulatory assistant or transcription factors (7SK RNA), (B2 RNA), and telomere maintenance is also shown.
nuclear ribonucleoprotein small sound that is associated with a set of complex with a specific protein, always snRNA is large “snurps” It is the (human origin). Each human-derived particles are composed of proteins of human origin specific snRNA synthesis of some proteins, and SM,. known as the snRNA of the most common components of these complexes: the U6 snRNA and the U5 snRNA, the U4 snRNA, the U1, U2 snRNA of snRNA. Nomenclature of them is derived from its high uridine content. snRNA was accidentally discovered in the experimental gel during electrophoresis in 1966. Are found in the gel of RNA type unexpected, it was investigated. Further analysis indicated that Urijireto have high RNA These are established in the core are shown.
snRNA of the large group, also known as (snoRNAs) small nucleolar RNA. These plays an important role in the biosynthesis of the RNA, using the chemical modification of other genes and (rRNAs), (the tRNA’s and snRNA) ribosomal RNA is a small RNA molecule RNA. Called (RNA over a small body Haar specific) scaRNAs, they are located in Cajal body nucleolus (major sites for synthesizing RNA) wherein eukaryotic cells.
general characteristics of two consistency, and based on the related factor protein, can be divided into two classes frequently snRNA. First, research class is also known as RNA classes of Sm more widely. SM-class snRNA’s are transcribed by RNA polymerase II. The pre-snRNA was prepared nuclear monomethylguanosine cap 5 ‘and transcription. Then, they have been exported to the cytoplasm for further processing. stem cap 3 ‘5 by trimethylguanosine in the cytoplasm of the snRNA – ‘to form, and the three required for recognition survival motor neuron receives a cleaning “3 (SMN) complex.’ methylation loop structure stem structure. This complex, is required to pay back the people from the nucleus then. 5 ‘cap. U1, U2, class snRNA of the Sm is a uridine all of these (to RNP) to stable ribonucloproteins assembling the snRNA of except for the foundation or removal. drag spliceosome of U7 form intron, including, U5, U7, U11, U12 inch of rich snRNA U4, U4atac, it is an important aspect of post-transcriptional modification, it eukaryotes only may operate in Purihisuton mRNA processing, the. U7 snRNA performed cores was found.
Second class, the snRNA of LSM-class, ending with a stretch of uridine forming the binding site of the ring heteroheptameric LSM individual proteins, 3 ‘stem-loop and monomethylphosphate cap is included. Unlike snRNA of LSM-class is a class of snRNA of Sm, never leave the nucleus and transcription by RNA polymerase III. The LSM-class snRNA known only two, there is U6atac and U6.
Spliceosome is a key component of an essential step in the maturation of eukaryotic precursor messenger RNA. The error of another nucleotide, may devastating reliable for RNA processing and cell, reproducible method and is needed to ensure the survival of the cells. Is composed of more than 150 proteins and (U6 and U1, U2, U4, U5) small nuclear RNA of five, the protein-RNA complex large-scale, some in the spliceosome. Have (snRNPs) protein form ribonucleoprotein complex that their associated that bind to specific sequences of pre-mRNA substrates of snRNA, together.
The transesterification reaction using two consecutive results of this complex process. These reactions generate ligation freedom and lariat introns exons 2 to form the mature mRNA. I There are different classes spliceosome 2. Main class, type intron splice U2 mainly a eukaryotic cell much richer. The first step in splicing and related proteins human U1 is connected to the 5 ‘end of the splice hnRNA. This creates a complex task to limit the hnRNA splicing of time. hnRNA expose nucleotide favorable for splicing is then recruited to the spliceosome-binding site of human U2 to form complex A., change confirmation of U2 human origin of the complex of human origin. After confirming the change, it was reorganized and join to form a structure known as a complex B, complex C is formed, complex U4/U5/U6 three derived from human catalysis It is active spliceosome for.
In addition to being a major spliceosome complex this, there is a small spliceosome much less. This complex is made up U11, U12, U4atac, in U5 snRNPs and U6atac. SnRNPs These are functional analogs of use snRNPs in spliceosome most. Intron of minor Sprouse iso Saum splice U-12 type. Intron, the following two different splice sites: mainly the U12-type intron, whereas having AC 5 ‘and 3’ ends thereof, U2-type intron splice ‘and 3’ GT-AG 5 I have a site. To perform its functions in a different way minor Supra iso Saum, from the main spliceosome