RNA Transcription Prokaryotic System

Cells contain three major classes of RNA, i.e. messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), all of which participate in protein synthesis and are synthesized from DNA templates by DNA dependent RNA polymerase in the process termed transcription (Eckstein and LiUey, 1997 Moldave, 1981). 

Only one RNA polymerase catalyzes the synthesis of all three classes of RNA in prokaryotes. mRNA is transcribed from DNA template carrying genetic codes necessary for protein synthesis. mRNA, which encodes for one protein is called monocitronic, whereas mRNA encoding for more than one protein are referred to as polycitronic. Prokaryotic mRNA is polycitronic and prokaryotic transcription occurs concomitantly with translation. 

The prokaryotic processes pertaining to general featnres of the RNA transcription will be considered first in this subsection and the enkaryotic processes will be highlighted in the next subsection. 

2 Initiation of polymerization. RNA polymerase has two binding sites for NTPs the initiation site for ATP/GTP and the elongation site for substrate NTPs. Most RNA begins with a purine at the 5 -end. The 3 -OH of the first nucleotide at the initiation 

4 Chain termination. Two types of transcription termination operate in prokaryotes  

---