MGY377H1 Midterm: Study notes for midterm

63 views2 pages

redtermite204

26 Dec 2011

School

UTSG

Department

Molecular Genetics and Microbiology

Course

MGY377H1

Professor

William Navarre

For unlimited access to Study Guides, a Grade+ subscription is required.

Document Summary

Coordinated transcriptional regulatory system that enables cell to turn on different repair enzymes in response to dna damage. Involves: reca - protein that binds ssdna and facilitates dna recombination, lexa dna binding protein that represses transcription of a number of genes involved in dna repair. Under normal conditions, lexa repressor is abundant in cell, binds dna to keep levels of reca and uvrab and other genes low. When dna damage occurs, reca recruited to single stranded dna: lexa is cleaved, other genes that were repressed now induced. Positive feedback: lexa controls own expression, when damage is repaired, lexa shut down its own expression, turning off the response. Damage to dna if extensive, amount of lexa in cell will drop a lot. Activate expression of polymerase like umucd that can copy even damaged templates by guessing what the correct sequence is: lots of errors introduced. Alteration in base structure that is not repairable. Activation of prophages into lytic cycle ***

Related Questions

lex A is an E.coli gene whose product regulates the transcription of certain target genes that are located at different positions in the bacterial chromosome. Identified target genes appear to be involved in DNA repair and recombination. Under normal conditions, the LexA protein binds near and represses transcription of target genes; however, when the cell experiences significant DNA damage caused by environmental mutagens, the LexA protein is inactivated and transcription of the target genes occurs. Your research objective is to identify all of the target genes repressed by the LexA protein. (Assume that you have access to a DNA microarray consisting of sequences representing each of the genes in the E. coli genome.) As the starting point for your work, you isolate a lexA mutant strain that produces no functional LexA protein. Briefly describe an experiment that uses a functional genomics approach to identify all of the LexA target genes. Give the basic steps of the experiment and show how it would allow you to achieve your objective.

lex A is an E. coli gene whose product regulates thetranscription of certain target

genes that are located at different positions in the bacterialchromosome.

Identified target genes appear to be involved in DNA repair andrecombination.

Under normal conditions, the LexA protein binds near andrepresses

transcription of target genes; however, when the cellexperiences significant

DNA damage caused by environmental mutagens, the LexA proteinis

inactivated and transcription of the target genes occurs. Yourresearch objective

is to identify all of the target genes repressed by the LexAprotein. (Assume that

you have access to a DNA microarray consisting of sequencesrepresenting each

of the genes in the E. coli genome.) As the starting point foryour work, you

isolate a lexA mutant strain that produces no functional LexAprotein.

a) Briefly describe an experiment that uses a functionalgenomics approach to identify all

of the LexA target genes.

b) Give the basic steps of the experiment and show how it

would allow you to achieve your objective

lex A is an E. coli gene whose product regulates thetranscription of certain target
genes that are located at different positions in the bacterialchromosome.
Identified target genes appear to be involved in DNA repair andrecombination.

Under normal conditions, the LexA protein binds near andrepresses
transcription of target genes; however, when the cell experiencessignificant
DNA damage caused by environmental mutagens, the LexA proteinis
inactivated and transcription of the target genes occurs.

Your research objective
is to identify all of the target genes repressed by the LexAprotein. (Assume that
you have access to a DNA microarray consisting of sequencesrepresenting each
of the genes in the E. coli genome.) As the starting point for yourwork, you
isolate a lexA mutant strain that produces no functional LexAprotein.

Briefly
describe an experiment that uses a functional genomics approach toidentify all
of the LexA target genes. Give the basic steps of the experimentand show how it
would allow you to achieve your objective.

beigemink26

MGY377H1 Midterm: Study notes for midterm

Document Summary

Get access

Related Documents

MGY377H1 Lecture Notes - Lecture 23: Site-Specific Recombination, Quorum Sensing, Bacteriophage

MCELLBI C148 Lecture Notes - Lecture 13: Regulon, Rna-Seq, Repressor Lexa

Biology And Biomedical Sciences BIOL 2960 Study Guide - Midterm Guide: Tumor Suppressor Gene, Dna Mismatch Repair, Pribnow Box

Related Questions