In this article we will discuss about the processing of pre-tRNA in E.coli and yeast. In prokaryotes, there are many operons (e.g. 7 genes in E. coli) which are separated by spacer sequences. Mature tRNA molecules are generated by processing longer pre-tRNA transcripts. Through a specific step, RNases D, E, F and P generate these mature tRNA molecules by exo-and [...]
In this article we will discuss about the processing of mRNA in prokaryotes and eukaryotes. In prokaryotes, there is a little or no processing of mRNA transcripts. Prokaryotic mRNA is degraded very rapidly from 5' end. Therefore, to rescue from degradation it is translated before being finally transcribed. Ribosomes assemble on unfinished mRNA and first cistron (protein coding region) can [...]
The tRNA, mRNA and rRNA are involved in the process of transcription. However, an enzyme transcriptase i.e. DNA-dependent RNA polymerase is required for the synthesis of RNA by using ribonucleotide triphosphates i.e ATP, GTP, CTP and UTP. Structure and function of RNA polymerase are described herewith. 1. RNA Polymerase: On a DNA template elongation of RNA chain at each step [...]