Question

Transcribe and translate the genes shown below. Assume that transcription starts five bases past the TATAAA box and ends five baes past the Poly-A site. Label the ends of all DNA and RNA strands. TATA box is on the NON-TEMPLATE (coding) strand. Poly A site= AATAAA is also on the NON-TEMPLATE (coding) strand.

1. 3’GGGCATTGGATATTTCGCCAAAGGGGGGTATACCCCAAACCGGCACCCGCATTGCAGGAGAGAATTCGTCCGGTTATTTCGGCG5’ 5’CCCGTAACCTATAAAGCGGTTTCCCCCCATATGGGGTTTGGCCGTGGGCGTAACGTCCTCTCTTAAGCAGGCCAATAAAGCCGC3’

2. 3’AATGCAAATAAGGATGGGGAGCAGCCTAGACCCCAAACCGGCATTGTATCGTCCGGCTCGGTTTAAATATCGGC5’ 5’TTACGTTTATTCCTACCCCTCGTCGGATCTGGGGTTTGGCCGTAACATAGCAGGCCGAGCCAAATTTATAGCCG3’

Answer 1

• it is give in the question translation happen 5 bases upstream the TATAAA box and terminates in 5 past upstrem poly A chain
• during the transcription the DNA strand with polarity 5' to 3' is transcribed into mRNA with polarity 5' - 3'
• the only difference between this DNA strand and the mRNA strand is the T is replaced by U nucleotide
• the mRNA forms the coding strand nd the other strand of the DNA will act as template strand

1.mRNA strand

5' UAACCUAUAAAGCGGUUUCCCCCCAUAUGGGGUUUGGCCGUGGGCGUAACGUCCUCUCUUAAGC3'

DNA template strand

3'ATTGGATATTTCGCCAAAGGGGGGTATACCCCAAACCGGCACCCGCATTGCAGGAGAGAATTCG5'

from 28th base the translation starts because translation starts with codon AUG coding for methionine

translates as Met - Gly - Phe - Gly - Arg - Gly - Arg - Asp - Val - Leu - Ser - stop