Making ends of RNA
RNA splicing
Primary Transcript
Primary Transcript-the initial molecule of RNA produced--- hnRNA
hnRNA-heterogenous nuclear RNA
In prokaryotes, DNA →RNA →protein in cytoplasm concurrently
In eukaryotes nuclear RNA >> Cp RNA
Types of RNA processing
A) Cutting and trimming to generate ends:
rRNA, tRNA and mRNA
B) Covalent modification:
Add a cap and a polyA tail to mRNA
Add a methyl group to 2’-OH of ribose in mRNA and rRNA
Extensive changes of bases in tRNA
C) Splicing
pre-rRNA, pre-mRNA, pre-tRNA by different mechanisms.
