Question

In the following primary RNA sequence, uppercase letters represent exonic sequences; lowercase letters represent intronic sequences.

5' CUUCUUAAAUGAUCAGUUGgucccuaauuagaugacuaccuugagUUUGCGAUUGAA AUGAUGUAAAAAAAAAUAA
Write out the mature mRNA (after splicing). Label the 5′UTR, the 3′UTR, and the open reading frame (written as a series of codons, from start codon to stop codon).

Answer 1

The mature mRNA after splicing the provided primary RNA sequence consists of exonic sequences with labeled 5'UTR, ORF, and 3'UTR. The 5'UTR and 3'UTR are untranslated regions, while the ORF contains the protein-coding region starting at a start codon and ending at a stop codon.

Step-by-step explanation:

After splicing the primary RNA sequence, the mature mRNA is produced by removing the intronic sequences (lowercase letters). This mature mRNA includes exonic sequences (uppercase letters), the 5' untranslated region (5'UTR), the open reading frame (ORF), and the 3' untranslated region (3'UTR). For the provided sequence, the process will remove the lowercase letters, and the mature mRNA with labels would look like this:

5' 5'UTR CUUCUUAAA ORF AUGAUCAGUUG UUUGCGAUUGAA AUGAUG 3'UTR UAAAAAAAAAUAA 3'

The 5'UTR is the untranslated region at the start of the mRNA which is not translated into protein. The ORF starts with the start codon AUG and ends at a stop codon (UAA, UAG, or UGA), but in the provided sequence, we do not see a termination codon within the sequence of exons, so it is assumed that it ends with the end of the provided sequence. The 3'UTR is the region after the ORF that is not translated into protein and often contains regulatory regions that can affect mRNA stability and translation efficiency.