BIO 340 Activity # 7: Transcription and translation I. Use the DNA sequence belo

Question

BIO 340 Activity # 7: Transcription and translation

I. Use the DNA sequence below, which encodes a prokaryotic gene to answer the following questions.

1-ATGAGGAGTT    11-GACACACAAG    21-AGGAGGTAGC    31-AGTATGGGTA 41-TAATCTAATG

51-CGTAATTGAG    61-GAGGTAGTTG    71-ACGTATGAAT    81-AGTTAACGTA    91-CGGGGGGGAA

101-ACCCCCCCTT    111-TTTTTTTTTC    121-GAGCAATAAA    131-AGGGTTACAG    141-ATTGCATGCT

a) Write down the corresponding sequences, find them in the sequence above and label them:

-35 Consensus sequence: __TTGACA___________ (label as -35)

-10 Consensus sequence (Pribnowbox): __TATAAT_____ (label as Pribnow)

Shine-Dalgarnosequence in corresponding mRNA: _AGGAGGU_________ (label as SD)

Start (initiation) codon in corresponding mRNA: __AUG___  (label as start)

Stop (termination) codon in corresponding mRNA: _______ (label as stop)

b) What region of this prokaryotic DNA sequence will be transcribed into mRNA? Circle one. 1-131 71-119 74-149 (54-119

c)   What will the sequence be for the protein translated from this mRNA?

d)   Where is the 3’UTR?  Circle one. 9-131 41-119 81-141 87-119

I was able to identify the first couple parts of part a.) and bolded them in the DNA sequence. I'm just not sure about the other parts. Does the start codon ATG begin after the SD sequence (75-77)? It looks like the stop codon TAA (UAA) is only a few bp's away (84-86). Am I confused, because there is 'another' SD sequence between the two promoters (21-27), is that the one I'm supposed to use?

Explanation / Answer

a) in prokartotes

In prokaryotes, various interconnected polypeptide sequences are bringing on the same template of mRNA. All sequence present on the mRNA strand has its own binding site of ribosome, start and stop codons. As long as transcrpition takes place in the the cytoplasm, translation can start before the compleation of transcription.

Prokaryotic transcription is the method in which messenger RNA transcripts of bacterial genetic material are produced, get translated for the protein production. In prokaryotes, transcription as well as translation can occur simultaneously in the cytoplasm. RNA polymerase binds to the promoter sequences to initiate the transcription, during elongation RNA polymerase read the template in the 3' - 5' direction and build mRNA strand in 5' -3' by joining the 5'-PO42-.of an incoming nucleotide triphosphate to the 3' OH of the precursor residue. And terminates at the terminator sequence

Prokaryote translation starts with the amino acid N-formylmethionine (f-met),  polypeptide chain elongation is facilitate by guanosine triphosphate (GTP) then terminates with the help of release factor at a stop codon, bond breaks between protein and the tRNA, result in the detachment of the ribosome subunits.

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