The following DNA sequence represents a eukaryotic gene. Indicate which is the t
ID: 87970 • Letter: T
Question
The following DNA sequence represents a eukaryotic gene. Indicate which is the template and which is the coding strand, determine where transcription begins (assume it ends at the end of the sequence presented), and write out the nucleotide sequence of the initial transcript. You need to process the initial transcript to make an mRNA (there is an intron in the gene: using the information about splicing on pp. 306-307 of your textbook, locate and remove the intron) and write out the sequence of the completely processed mRNA. Finally, translate the mRNA and write out the amino acid sequence of the encoded polypeptide. 5'- ACCGGCCTCTCTCTCACACACAGTACGGCGTTTATTGGGACTTCAAATCATAT GGCCATTACAAGCCCTGCAGAAAGGGAAGGCGAAGCTCAGGATAAGTA... 3 ' - TGGCCGGAGAGAGAGTGTGTGTCATGCCGCAAATAACCCTGAAGTTTAGTATA CCGGTAATGTTCGGGACGTCTTTCCCTTCCGCTTCGAGTCCTATTCAT... ..CAGGTGACACTCTACTCACCGGATAAGTATTGTCATCTCCCAAGGGGGTGAATATCCGCGCATCCGCTTTATATCGCCTGATTAACGCAGTCCTACACAAT- 3' ..GTCCACTGTGAGATGAGTGGCCTATTCATAACAGTAGAGGGTTCCCCCACTTATAGGCGCGTAGGCGAAATATAGCGGACTAATTGCGTCAGGATGTGTTA- 5'Explanation / Answer
Template strand is the DNA strand which acts as a template for the RNA synthesis. RNA polymerase acts on this strand from 3' to 5' end.
Template strand --------------> 3' -TGGCCG.....GTGTTA -5'
Coding strand determines the sequence of RNA. RNA contains uracil insted of thymine. It is read from 5' to 3' end.
Coding strand -----------------> 5' -ACCGGC....CACAAT -3'
In eukaryotic gene, transcription begins 10 base pairs downstream of promotor region. The promotor region is recognised by the presence of TATA box in coding strand.
Nucleotide sequence of the initial transcript is 5'-AACGCAGUCCUACACAAU-3'