LABORATORY REVIEW
MOLECULAR BIOLOGY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Polyadenylation
|
|
|
Splicing
|
|
|
Capping
|
|
|
Post transcriptional processing
|
Detailed explanation-1: -This process is called capping. Q. hn-RNA undergoes two additional processing. In one of them an unusual nucleotide (methyl guanosine triphosphate) is added to the 5’-end of hnRNA.
Detailed explanation-2: -5’ End Capping The capping process replaces the triphosphate group with another structure called the “cap". The cap is added by the enzyme guanyl transferase. This enzyme catalyzes the reaction between the 5’ end of the RNA transcript and a guanine triphosphate (GTP) molecule.
Detailed explanation-3: -5′-end capping occurs very early during Pol II transcription, typically after the synthesis of ∼20 nucleotides of the pre-mRNA. Capping has been linked to splicing and 3′-end processing of the pre-mRNA, and the export of the mature mRNA.
Detailed explanation-4: -The 5’ cap is added to the first nucleotide in the transcript during transcription. The cap is a modified guanine (G) nucleotide, and it protects the transcript from being broken down. It also helps the ribosome attach to the mRNA and start reading it to make a protein.