Question

Once raw sequence data have been obtained for a genomic region, functional features present in that region are identified and cataloged. This process is called genome annotation.

The genomic DNA sequence below is a 120-nucleotide fragment of the region containing the human insulin gene. The first 50 nucleotides of the human insulin mRNA are shown below the genomic DNA sequence.
₁₀ ₂₀ ₃₀ ₄₀
Genomic TTGACAGGTA TTGACAGGTA TTGACAGGTA TATAAAGCCA
DNA ₅₀ ₆₀ ₇₀ ₈₀
GCGGGGGCCC AGCAGCCCTC AGCCCTCCAG AGCCCTCCAG
₉₀ ₁₀₀ ₁₁₀ ₁₂₀
ATCAGAAGAG ATCAGAAGAG AGGTCTGTTC CAAGGGCCTT

mRNA AGCCCUCCAG GACAGGCUGC AUCAGAAGAG GCCAUCAAGC

AGAUCACUGU

Using these two sequences, determine if the following functional features are present in the genomic DNA sequence: TATA box, start of translation, start of transcription, and first intron.

Answer 1

The genomic DNA sequence contains a TATA box and a potential start of transcription, however, it does not contain the start codon or any introns.

Step-by-step explanation:

The genomic DNA sequence provided contains the information necessary to identify certain functional features.

1. TATA box: The TATA box is a sequence of nucleotides that serves as a binding site for RNA polymerase during the initiation of transcription. In the given sequence, the TATA box is located at positions 70-74 (AGCCA).

2. Start of translation: The start codon (AUG) marks the beginning of translation. In the mRNA sequence, the start codon is located at positions 95-97. However, the provided genomic DNA sequence doesn't contain the specific start codon.

3. Start of transcription: Transcription begins at the promoter region, which is usually located upstream of the coding region. In the given sequence, the start of transcription is indicated by the TATA box at positions 70-74.

4. First intron: An intron is a non-coding region within a gene that is transcribed into mRNA but is removed during RNA processing. In the provided genomic DNA sequence, there is no indication of the presence of an intron.