CHE.496/2009/Schedule/Oral presentations of part design/Group 4: Difference between revisions
(→Part 5) |
|||
| Line 19: | Line 19: | ||
'''Description''' | '''Description''' | ||
<p>[http://en.wikipedia.org/wiki/PpGpp ppGpp(p)] is an alarmone which gets produced in response to low levels of amino acids in the cell. Having a promoter responsive to this cellular signal would allow an engineered response certain types of stress on the cell. An example would be to put your synthetic metabolic network under control of a promoter that either gets directly inhibited by this signal or alternately, have such a promoter cause the production of an inhibitor for your synthetic genes.</p> | <p>[http://en.wikipedia.org/wiki/PpGpp ppGpp(p)] is an alarmone which gets produced in response to low levels of amino acids in the cell. Having a promoter responsive to this cellular signal would allow an engineered response certain types of stress on the cell. An example would be to put your synthetic metabolic network under control of a promoter that either gets directly inhibited by this signal or alternately, have such a promoter cause the production of an inhibitor for your synthetic genes.</p> | ||
'''Mechanism''' | |||
<p>ppGpp is produced by RelA and SpoT. RelA is associated with ribosomes and is activated when an uncharged tRNA is in the A position. The precise triggers for SpoT is not known but it is activated in response to nutrient limitations including carbon starvation. ppGpp binds to RNA pol. and affects its translational targeting. It represses rRNA synthesis and also activates the rpoS gene, which codes for [http://en.wikipedia.org/wiki/Sigma_38 σ<sup>38</sup>]. Promoters responsive to this RNAP/σ<sup>38</sup> could be activated in response to stress/starvation.</p> | |||
'''Source & References''' | '''Source & References''' | ||
# [http://dx.doi.org/10.1016/j.tim.2005.03.008 Magnusson et al. (2005) Trends in Microbiology 13, 236] | # [http://dx.doi.org/10.1016/j.tim.2005.03.008 Magnusson et al. (2005) Trends in Microbiology 13, 236] | ||
Revision as of 10:39, 12 April 2009
Group 4
- Members: Dan Tarjan & George Washington
Parts
- Part 1
- Description
- Source & References
- Part 2
- Part 3
- Part 4
ppGpp responsive promoter
Purpose
This promoter would be able to turn on genes in response to the stringent response mechanism in bacteria, including amino-acid and carbon starvation.
Description
ppGpp(p) is an alarmone which gets produced in response to low levels of amino acids in the cell. Having a promoter responsive to this cellular signal would allow an engineered response certain types of stress on the cell. An example would be to put your synthetic metabolic network under control of a promoter that either gets directly inhibited by this signal or alternately, have such a promoter cause the production of an inhibitor for your synthetic genes.
Mechanism
ppGpp is produced by RelA and SpoT. RelA is associated with ribosomes and is activated when an uncharged tRNA is in the A position. The precise triggers for SpoT is not known but it is activated in response to nutrient limitations including carbon starvation. ppGpp binds to RNA pol. and affects its translational targeting. It represses rRNA synthesis and also activates the rpoS gene, which codes for σ38. Promoters responsive to this RNAP/σ38 could be activated in response to stress/starvation.
Source & References
