Prescott's Microbiology
10th Edition
ISBN: 9781259281594
Author: Joanne Willey, Linda Sherwood Adjunt Professor Lecturer, Christopher J. Woolverton Professor
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 13, Problem 2CHI
You have isolated several E. coli mutants:
Mutant #1 has a point mutation (a single base-pair change) in the −10 region of the promoter of a gene encoding an enzyme needed for synthesis of the amino acid serine.
Mutant #2 has a mutation in the −35 region in the promoter of the same gene.
Mutant #3 is a double mutant with mutations in both the −10 and −35 region of the promoter of the same gene.
Only Mutant #3 is unable to make serine. Why do you think this is so?
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When a region of DNA that contains the genetic information for a protein is isolated from a bacterial cell and inserted into a eukaryotic cell in a proper position between a promoter and a terminator, the resulting cell usually produces the correct protein. But when the experiment is done in the reverse direction (eukaryotic DNA into a bacterial cell), the correct protein is often not produced. Can you suggest an explanation?
You are studying a human gene, and try to express the protein in E. coli bacterial cells. To do this, you use lab cloning techniques to create an expression vector - a circular piece of DNA (plasmid) which can replicate within E. coli, and which contains an appropriate E. coli promoter sequence before the human protein sequence. Note that the sequence used is the final mRNA protein coding sequence, with all introns removed.
You can detect that some of the protein is produced, but it's a very small amount. Luckily you included a positive control, which uses the same expression vector, and find that the control E. coli protein is expressed to high levels under the same conditions. A colleague suggests that you transform your same expression vector into a 'humanized' strain of E. coli that is optimized for the expression of human recombinant proteins (this is a real thing!). You do this and see protein expression – woohoo!
If the genetic code is universal, why might a human gene be poorly…
Chapter 13 Solutions
Prescott's Microbiology
Ch. 13.1 - MICRO INQUIRY Based on what we now know about...Ch. 13.1 - Retrieve, Infer, Apply 1. Briefly summarize the...Ch. 13.1 - Retrieve, Infer, Apply 2. Explain how protein was...Ch. 13.2 - MICRO INQUIRY To which carbon of ribose...Ch. 13.2 - MICRO INQUIRY How many H bonds are there between...Ch. 13.2 - Prob. 3MICh. 13.2 - Prob. 1RIACh. 13.2 - Retrieve, Infer, Apply What does it mean to say...Ch. 13.2 - Retrieve, Infer, Apply Amino acids are described...Ch. 13.3 - MICRO INQUIRY What provides the energy to fuel...
Ch. 13.3 - MICRO INQUIRY What is the difference between...Ch. 13.3 - MICRO INQUIRY Why cant DNA polymerase I perform...Ch. 13.3 - Retrieve, Infer, Apply How many replicons do...Ch. 13.3 - Retrieve, Infer, Apply Describe the nature and...Ch. 13.3 - Retrieve, Infer, Apply Outline the steps Involved...Ch. 13.3 - Retrieve, Infer, Apply What is the end replication...Ch. 13.4 - Why is the nontemplate strand called the sense...Ch. 13.4 - Retrieve, Infer, Apply The coding region of a gene...Ch. 13.4 - Which strand of a gene has sequences that...Ch. 13.4 - Briefly discuss the general organization of tRNA...Ch. 13.5 - MICRO INQUIRY Are the -35 and -10 regions...Ch. 13.5 - Retrieve, Infer, Apply Outline the transcription...Ch. 13.5 - Retrieve, Infer, Apply What is a polycistronic...Ch. 13.5 - Retrieve, Infer, Apply What is a consensus...Ch. 13.5 - Tabulate the similarities and differences between...Ch. 13.6 - Prob. 1MICh. 13.6 - Retrieve, Infer, Apply List the punctuation codons...Ch. 13.6 - What is the difference between a codon and an...Ch. 13.6 - Retrieve, Infer, Apply What is meant by code...Ch. 13.6 - Retrieve, Infer, Apply Is the genetic code truly...Ch. 13.7 - MICRO INQUIRY Why is simultaneous transcription...Ch. 13.7 - MICRO INQUIRY What would be the outcome if an...Ch. 13.7 - MICRO INQUIRY Why would it be impossible for...Ch. 13.7 - MICRO INQUIRY What provides the energy to fuel...Ch. 13.7 - Retrieve, Infer, Apply In which direction are...Ch. 13.7 - Retrieve, Infer, Apply Briefly describe the...Ch. 13.7 - Retrieve, Infer, Apply What are the translational...Ch. 13.7 - Retrieve, Infer, Apply Tabulate the nature and...Ch. 13.7 - Retrieve, Infer, Apply How many ATP and GTP...Ch. 13.8 - MICRO INQUIRY What are two distinguishing features...Ch. 13.8 - Retrieve, Infer, Apply What are molecular...Ch. 13.8 - Retrieve, Infer, Apply Would an intein-containing...Ch. 13.8 - Retrieve, Infer, Apply Give the major...Ch. 13.8 - Retrieve, Infer, Apply Which translocation or...Ch. 13.8 - Prob. 5RIACh. 13 - Streptomyces coelicolor has a linear chromosome....Ch. 13 - You have isolated several E. coli mutants: Mutant...Ch. 13 - DNA polymerase I (Pol I) of E. coli consists of...Ch. 13 - Prob. 4CHI
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