A eukaryotic proteinencoding gene contains two introns and t

A eukaryotic protein-encoding gene contains two introns and three exons: exon 1-intron 1-exon 2-intron 2-exon 3. The 5\' splice site at the boundary between exon 2 and intron 2 has been eliminated by a small deletion in the gene. Describe how the pre-mRNA encoded by this mutant gene would be spliced. Indicate which introns and exons would be found in the mature mRNA of this mutant. The open reading frame (ORF) begins with ___ and ends with ___ codon Referring to the genetic code table below, answer this question: If a tRNA has an anticodon with the sequence 5\'-CAG-3\', which amino acid does it carry? An mRNA has the following sequence: 5-AUG UAC UAU GGG GCG UAA-3\' Write the corresponding coding DNA strand Translate the mRNA, indicating directionality of the polypeptide The sequence below represents DNA sequence of a small hypothetical protein coding eukaryotic gene X. Nucleotides in red match to mature mRNA of the wild type copy of gene X. Based on protein sequence analysis you know that ATG in bold is the beginning of the CDS. Underlined areas indicate locations of mutations identified in some individuals. Based on your sequence analysis, answer questions below.

Solution

7. pre-mRNA – exon1-intron1-exon2-intron2-exon3

Mature mRNA – exon1-exon2-intron2-exon3

8. ORF begins with AUG codon and ends with UAA or UGA or UAG codons

9. anticodon sequence- 5’-CAG-3’

Therefore codon- 5’-CUG-3’ which codes for Leucine. The tRNA contains Leucine amino acid.

10. 10.1. coding strand is identical to mRNA synthesized except that thymine is replaced by uracil in mRNA.

Coding strand sequence- 5’-TTA CGC CCC ATA GTA CAT-3’

10.2. POLYPEPTIDE –N- Met-Tyr-Tyr-Gly- Ala-COOH-STOP