lecture_23 - Lecture23 RegulatoryResponses SOSandHeatShock...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 23 Regulatory Responses: SOS and Heat Shock Reading 19.1 19.3, 19.4
Image of page 1

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

View Full Document Right Arrow Icon
SOS: Mechanism to read through damaged and/or modified DNA
Image of page 2
What happens when cells are exposed to DNA damaging agents DNA damage occurs and causes, nicks, gaps, breaks, etc.
Image of page 3

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

View Full Document Right Arrow Icon
Key enzymes: RecA: DNA recombination, activator for the system LexA: Repressor of SOS genes SulA: inhibitor of FtsZ, substrate for Lon Protease SOS inducable Lon: Protease, degrades SulA UmuDC : inhibit PolII proofreading (error prone), SOS inducable PolII: repair polymerase SOS inducible UvrABD: UV induced excision repair SOS inducible RuvA,B, RecN: Double strand Gap/break repair SOS inducible
Image of page 4
Model: In response to ss DNA fragments, nicks etc. Causes the activation of RecA Activated RecA (RecA*), aids in the autocleavage of LexA Removal of LexA causes initiation of SOS genes Repair functions to “fix” damage no more damage, leads to inactivation of RecA* LexA accumulates and shuts down the system
Image of page 5

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

View Full Document Right Arrow Icon
Image of page 6
Under these conditions, cells require time to “fix” the damage Cell’s arrest cell division.
Image of page 7

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

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern