I believe the answer is the first one you listed,
Hope this helps..
Answer:
Mutation occurred in ribosome binding site that serves as binding site for 30S ribosomal subunit of <em>E. coli</em> and allows the process of protein synthesis to begin.
Explanation:
The initiation of protein synthesis in bacteria requires binding of the ribosome to the ribosome binding site. The ribosome binding site in bacteria consists of the initiation codon "AUG" and the preceding Shine-Dalgarno sequence. The AUG initiation codon and Shine Delgrano sequence are around 10 bases apart.
The sequence is polypurine hexamer and is represented by 5' ...AGGAGG...3'. Shine-Delgrano sequence is complementary to the conserved sequence present at the 3' end of 16SrRNA of the 30S subunit of the bacterial ribosome. Binding of Shine Delgrano sequence of ribosome binding site and the complementary sequence of the 30S ribosomal subunit marks the first step in the initiation of protein synthesis.
Any mutation in the ribosome binding site would not allow the process of protein synthesis to start or would reduce the rate of the initiation of protein synthesis.
Because it is not the dominant allele, it is the recessive allele so it is not shown.
A, a node is where the different section either split or interconnect in a cladogram.
