Problem set 4

Problem set 4 - Problem set #4 From Griffiths et al...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Problem set #4 From Griffiths et al textbook: Chapter 13 : problems 10, 17, 18, 20. Additional Questions: A) What would happen to the expression of the entire RNA for Trp operon in the presence and absence of excess tryptophan in an E. coli strain that carried a missense mutation in the Trp R gene, such that TrpR protein (the repressor) could no longer bind tryptophan (but was otherwise unchanged)? What would happen to the expression of the first 140 nucleotides? Would such a mutation be dominant or recessive? B) Explain how the presence of glucose in the external environment represses transcription of genes in the lac operon. 17. (12 points) What would be the effect on the expression of the trp operon for each of the following mutations (circle one answer)? Note whether the mutations would be dominant or recessive and if they would act in cis, trans or both. The sequence of the trp leader sequence from E. coli is shown below. i) A pair of missense mutations that alter the Trp codons in the leader (shown above) such that they now encode for Ser. This would:increase expression in the presence of high Trp levels increase expression in the presence of low Trp levels increase expression under all conditions
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/21/2008 for the course BIOL 202 taught by Professor Kieber-hogan during the Spring '08 term at UNC.

Page1 / 2

Problem set 4 - Problem set #4 From Griffiths et al...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online