The double-stranded DNA sequence for the coding region of a short peptide is:
1, Which strand of DNA, top or bottom is transcribed by RNA polymerase.Explain.
2, A mutation at the second triplet on the coding strand deletes on of the A-T pairs and creates a frameshift mutation. what is the sequence of the peptide now?
1. The bottom strand will be transcribed, because its 3'-end has a TAC triplet. It corresponds to AUG start codon in mRNA. The top strand cannot result in mRNA with the start codon.
2. The resulting DNA sequence is 3' TAC-AAA-GCT-GCA-CGC-TAA-CT 5' It will result in mRNA with a sequence: 5' AUG-UUU-CGA-CGU-GCG-AUU-GA 3'