Transcription

Transcription is the first step in gene expression that are copied into RNA enzymatic RNA polymerase specific segment of DNA. RNA and DNA is a nucleic acid base pairs using a nucleotide having additional languages ​​may be by the action of the right enzyme to convert back and forth to the RNA from the DNA. During transfer, further, DNA sequence results in antiparallel strand RNA, and is read by RNA polymerase. In contrast, thymine (T) would not occur in the complement of the DNA transcription, and in each case, DNA replication leads to complement RNA containing uracil (U). Further, in contrast to the replication of DNA, DNA is synthesized and does not include a transfer RNA primers to initiate synthesis of RNA.

Transcription

Proceed transcription in stage 5 or 6 to move like a wave along the DNA. Sigma factor of one or more starts to allow the binding of RNA polymerase promoter DNA, transcription of a gene. To transcription bubble movement of the RNA polymerase, such as zipper slider to split the double-stranded DNA molecule to double-stranded unpaired nucleotide DNA by breaking the hydrogen bonds of complementary nucleotides during DNA. RNA polymerase adds a matching RNA nucleotide is coupled to the DNA nucleotides complementary to one strand of the DNA. Phosphate backbone is formed – RNA, the sugar and the support by RNA polymerase to form RNA.

Hydrogen bonds RNA helix DNA segments twist release the RNA strand newly synthesized. If you have a nucleus of RNA, cells, and outputs it to the cytoplasm through the nuclear pore complex and (additional cap 5’UTR and 3’UTR poly A tail) for further processing. Transcription is the first step leading to gene expression. Is called a transfer unit, a stretch of DNA transfer has genes encoding the at least one RNA molecule. Thereafter, the process of translation, the result of the transfer messenger RNA is used to produce this protein (mRNA), transcribed genes, when encoding the protein. Alternatively, (for example, micro-RNA, etc. lincRNA) ribosomal RNA and or (rRNA gene) transfer RNA (the tRNA), transcribed genes encodes a ribozyme or non-protein components, the assembly process non-coding RNA genes get.

The transfer unit of DNA encoding the protein, and a sequence not only can not only convert the protein (coding sequence), controls the regulatory sequences direct Finally, to adjust the synthesis of this protein . Coding sequence is called (ie, upstream) 5 president untranslated region of before (5’UTR), and coding sequence, a series of the following (downstream) 3 prime untranslated region regulatory sequences, (3 ‘UTR it is called). Transfer some correction mechanism, is because it is less effective than the control in the copy of DNA transcription, the accuracy of the copy DNA replication is low they.

As the replication of DNA, DNA is read from the 3’UTR → 5’UTR during transfer. On the other hand, RNA complementary is created by 5’UTR → direction 3’UTR. That is, the 5 ‘end was first created in base pairs. And is formed by anti-parallel strands of two DNA double helix, but is used to transfer only one of the two strands of DNA called the template strand. In comparison with only double-stranded DNA RNA, it is because it is single-stranded. Since sequences are the same (except substitution of uracil for thymine) RNA transcript fresh, DNA encoding the other chain is a (gap) direction. You can use the 3’UTR → 5’UTR circuit only need to Okazaki fragments seen in DNA replication is eliminated. End pre-start, start, promoter clearance, and elongation: transcription is divided into five stages.