A RNA polymerase

Figure Bl.9.9. Comparison of the distance distribution fiinction p(r) of a RNA-polymerase core enzyme from the experimental data (open circle) and the simulation data (using two different models). This figure is duplicated from [27], with pennission from Elsevier Science.

One of the dreams of present-day researchers is the construction of a minimal enzyme capable of making copies of oligonucleotides - a RNA polymerase. The ideal operation scheme is presented in the Figure 7.11. Here, the enzyme hrst covalently binds an activated trinucleotide, then a hexanucleotide can bind by... 

A. RNA polymerase sequentially polymerizes nucleotides on the DNA template to form an RNA copy of one of the A strp nds ... 

A) RNA polymerase II binds to a promoter that contains a TATA box... 

The reaction catalyzed by RNA polymerase, (a) RNA polymerase separates the two strands of DNA and produces an RNA copy of one of the two DNA strands, (b) Phosphodiester bond formation occurs as a nucleotide is added to the growing RNA chain. 

Initiation of transcription requires speeific recognition of a promoter DNA sequenee located upstream to the eoding sequenee of a gene by a RNA polymerase. This reeognition is preeeded by sequence-specific binding of one or more protein transeription factors to the promoter sequence. Additional proteins, which bind at or close to the promoter sequence may upregulate transcription and are known as enhancers. Other proteins, which bind to or close to the promoter, but whose binding prohibits action of RNA polymerase, are known as repressors. 

For amplification of the target, methodologies involving production of anti-sense RNA (aRNA) from a RNA polymerase T7 promoter engineered at the 3 end of the cDNA are widely used (see (8)). A popular commercial use of this technique is the MessageAmp aRNA kit from Ambion (www.ambion.com). Multiple rounds of amplification may be employed. 

Haracska L, Johnson RE, Prakash L, Prakash S (2005) Trf4 and Trf5 proteins oiSaccharomy-ces cerevisiae exhibit poly(A) RNA polymerase activity but no DNA polymerase activity. Mol Cell Biol 25(22) 10183-10189... 

Transcription may be divided into three phases initiation, elongation and termination. Transcription commences on the binding of a RNA polymerase at a specific site called a promoter on the... 

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