Question

On the sequence below: 1. Indicate the direction of transcription 2. Indicate which is the coding strand and which one is the template for the transcription 3. Write down the mRNA 4. Write down the protein clearly indicating the first codon on the mRNA(hint: find the Kozak sequence RCCAUGG to identify the first codon) 5. Introduce a nonsense mutation 3' AGTCGACTGGCATCAGACTACGCTGTGACTGATACGCGTTTTATTGGATCGCACCGCATACAGGGCCCCGGTACCGTCCAAAACT CCCGAGTAGTCAGATGTCAGCAGCGAAATATACGG 5' 5'TCAGCTGACCGTAGTCTGATGCGACACTGACTATGCGCAAAATAACCTAGCGTGGCGTATGTCCCGGGGCCATGGCAGGTTTTGAGGGCTCATCAGTCTACAGT CGTCGCTTTATATGCC 3'

Answer 1

1. Indicate the direction of transcription

The answer is The transcription always occurs from 5'>3'.

2. The template starnd is

The answer is

3'AGTCGACTGGCATCAGACTACGCTGTGACTGATACGCGTTTTATTGGATCGCACCGCATACAGGGCCCCGGTACCGTCCAAAACT CCCGAGTAGTCAGATGTCAGCAGCGAAATATACGG 5'

and coding strand is

5'TCAGCTGACCGTAGTCTGATGCGACACTGACTATGCGCAAAATAACCTAGCGTGGCGTATGTCCCGGGGCCATGGCAGGTTTTGAGGGCTCATCAGTCTACAGT CGTCGCTTTATATGCC 3'

3. Write down the mRNA

The answer is

As A codes U, T codes A, G codes C and C codes G, the mRNA will be

5'UCAGCUGACCGUAGUCUGAUGCGACACUGACUAUGCGCAAAAUAACCUAGCGUGGCGUAUGUCCCGGGGCCAUGGCAGGUUUUGAGGGCUCAUCAGUCUACAGUCGUCGCUUUAUAUGCC3'

4. Write down the protein clearly indicating the first codon on the mRNA(hint: find the Kozak sequence RCCAUGG to identify the first codon)

The answer is

The Kozak sequence is a consensus sequence which acts as a transcription initiation site for protein synthesis. The A acts as inition nucleotide in that consensus sequence.

1 AUG GCA GGU UUU GAG GGC UCA UCA GUC UAC AGU CGU CGC UUU AUA UGC C-- 51
1 Met Ala Gly Phe Glu Gly Ser Ser Val Tyr Ser Arg Arg Phe Ile Cys XXX 16

5. Introduce a nonsense mutation 3'

The answer is

1 AUG GCA GGU UUU GAG GGC UCA UCA GUC UAC AGU CGU CGC UUU AUA UGA C-- 51
1 Met Ala Gly Phe Glu Gly Ser Ser Val Tyr Ser Arg Arg Phe Ile Termination 16