High temperature and high hydrogen peroxide concentrations c

High temperature and high hydrogen peroxide concentrations can be detected in the cytoplasam of cells such as E.coli. Describe how each is sensed within the cytoplasm, at the molecular level, and identify a common feature between these two diferent mechanisms of sensing.

Solution

Bacterial transcription factors ( mailnly OxyR, PerR) are main sensors of H2O2 in E.coli bacteria.If the concentration of hydrogen peroxide increases in the cytoplasm, it leads to the oxidative damage and as a result cell fitness and survivility will decrease.

Usually bacteria survives because of the proteins being in their proper conformations. Enzymes are also a proteins. Enzymes have particular optimum temperature where they are functional. If the temperature increases from optimum their function either decreases or they becomes inactive. This might be due to conformational changes also that enzymes or other essential proteins do not function well and hence bacteria dies. Hence for the high temperature the sensors are protein or enzyme.

Common feature between these two sensing mechanism :

In the above two sensing cases the common feature is that the protein gets denatured.