Genetics  Exam II – Extra credit

Genetics                                  Exam II – Extra credit (due 5-15)                            Name________________

(8 points)

The following sequence contains two small genes in E. coli.  The -35 hexamers of both promoters are boxed.  Draw the product of transcription in the space below the diagram for the transcript from the stronger of the two promoters.  (note:  inverted repeats are signified by arrows over the complementary sequence).  For the purposes of this question, transcription termination in a r-dependent terminator occurs 7 bases beyond the end of the stem loop.  A r-independent terminator terminates as described in class.  Be sure to label the 5’ and 3’ ends of your RNA.  Draw your RNA with the stem loop structure (draw lines to represent H-bonds between the complementary base pairs in the stem loop).

Draw the product of translation of your mRNA in the space below.  The minimal Shine-Delgarno consensus sequence is 5’-AGGAGG-3’.  Label N- and C-termini.

How would you expect a T:A substitution of the base pair below the asterisk to affect the transcription and/or translation product(s).

Describe an intergenic suppressor(s) of the substitution mutation.  Note: If both transcription and translation are affected, it may require two different suppressors