POST TRANSCRIPTIONAL MODIFICATIONS Complete Process
POST TRANSCRIPTIONAL MODIFICATIONS: Introduction The flow of genetic information is relatively simple and fast in prokaryotes where both transcription and translation are coupled in the protoplasmic compartment. But in eukaryotes, the nuclear envelope is a hurdle in this smooth flow with transcription taking place in the nuclear compartment and translation in the cytoplasmic compartment. Besides, the product of transcription in eukaryotes is a raw transcript (called primary transcript or pre-RNA) which undergoes various chemical changes to become a functional molecule. The term RNA processing refers to all these chemical modifications necessary to generate a final RNA product from the primary transcript. Processing typically involves the addition or chemical modifications of specific nucleotides and also the removal of certain portions of precursor RNA (Table 5.1). Although processing is more often related to the eukaryotic system, nevertheless prokaryotic rRNAs and tRNAs (not mRNAs) a...