Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 2

Let's suppose a DNA mutation changes the consensus sequence at the 35 location in a way that inhibits factor binding. Explain how a mutation could inhibit the binding of factor to the DNA. Look at Figure 12.5 and describe two specific base substitutions you think would inhibit the binding of factor. Explain why your base substitutions would have this effect.FIGURE 12.5 Examples of 35 and 10 sequences within several E. coli promoters. This figure shows the 35 and 10 sequences for one DNA strand found in seven different E. coli promoters. The consensus sequence is shown at the bottom. The spacer regions contain the designated number of nucleotides between the 35 and 10 region or between the 10 region and the transcriptional start site. For example, N 17 means there are 17 nucleotides between the end of the 35 region and the beginning of the 10 region.