Messenger RNA

Is a large family of RNA molecules that can transmit the genetic information to specify the ribosome amino acid sequence of the protein product of gene expression RNA from DNA (mRNA is). As summarized in the central dogma of molecular biology, protein: after transfer of mRNA by RNA polymerase, mRNA was expressed in a polymer of amino acids. DNA, as RNA, the genetic information is encoded into a sequence of nucleotides that are located in each codon consisting of three bases. Except for the termination codon of the protein synthesis, codons each encoding a particular amino acid. Provide transfer RNA ribosomal RNA (of rRNA) and amino acids mediate the recognition of codon, which is the main component of the ribosome is a protein manufacturing equipment, the corresponding (tRNA is) this process of translation codon in the amino acid, RNA I need a type of two other.

The transfer, simple presence of tRNA molecule begins full disassembly eventually. During his life, one molecule of the mRNA may be edited processed and transported to previous translations. While prokaryotic molecules often, mRNA molecules of eukaryotes requires the transport and processing a wide range of. RNA is when it is transcribed from DNA. If necessary, the transfer time, DNA polymerase makes a copy of the DNA of gene mRNA. This process is similar in eukaryotes and prokaryotes. The essential difference is that it so that after the start of transcription is performed promptly processed to binding RNA polymerase in prokaryotes, the mRNA processing enzymes during transfer.

, In the processed products, the pre-mRNA or precursor mRNA, it is called the completely processed at a time, it is called mature mRNA or partially untreated short. processing of mRNA varies widely between archaea eukaryotes, and bacteria. MRNA in non-eukaryotic organisms are mature in nature of the transfer, and does not require treatment With the exception of rare cases. However, eukaryotic mRNA precursors, requires a large-scale processing. I is a modified nucleotide guanine that have been added to the 5 or “front” – (referred to as RNA m7G cap or methyl guanosine cap RNA cap, 7 RNA also) cap ‘end of the messenger RNA of eukaryotic transcription initiation soon after 5 ‘. 5 ‘cap 7 are linked via a connection and the transfer nucleotide 5′-5’-triphosphate, – the first is constituted by methylguanosine residue terminal. Her presence is important for recognition by protection from RNase and the ribosome.

Further cap attached to the transfer, the transfer, since each interact and displayed together. After the start of transcription, the 5 ‘end of the mRNA, download is synthesized attached to the cap synthetic complex associated with the RNA polymerase. This enzyme catalyzes the complex chemical reactions which are required for sealing the mRNA. Synthesis proceeds as biochemical reaction of multi-stage. Splitting is a process which is characterized in that it is modified to remove the areas that remain, including specific region of the non-coding sequences called introns, protein coding sequences called exons pre-mRNA. Sometimes, allows gene encodes multiple proteins, pre-mRNA message may be a spliced ​​many different ways. This process is called alternative splicing. Normally, drag is called spliceosome performed by RNA-protein complex but, RNA molecules, some are able to catalyze the splicing of its own.

Polyadenylation, and is connected to the part covalent bond polyadenylyl messenger RNA molecule. In eukaryotes, RNA of all but the histone molecules (of mRNA) was polyadenylated at the 3 ‘end. Poly protein (A) tail to help protect the mRNA from degradation by exonucleases. Also for the termination of transcription, polyadenylation is an important export of mRNA from the translation of the core. mRNA can in order to not interfere with the exonuclease degradation (A) tail act easily and poly now be polyadenylated in prokaryotes.

Immediately after transcription and polyadenylation of the RNA from the DNA. Transfer is complete, the chain mRNA is cleaved by the action of the endonuclease complex associated with the RNA polymerase. After the mRNA is cut, about 250 adenosine residues are added to the end of the 3 ‘cleavage site of the free. This reaction is catalyzed by a polymerase polyadenylation. As alternative splicing, and may be one or more embodiments of the polyadenylated mRNA. Polyadenylation site of mutation. The primary RNA transcript of a gene, cut with a poly A addition site, 100 to 200, is added to the 3 ‘end of the RNA. In this site, if you have changed the result of the stable mRNA and unusually long. Beta globin several mutations to change this site: AATAAA is an example -> AACAAA. Moderate anemia is the result.