Subsystem: Oxidative stress
This subsystem's description is:
Tis SS combines functions belonging to different pathways. However they all belong to organisms response to different types of oxidative stress.
Oxidative stress is the main environmental problem which nearly all organisms should deal with. In case of pathogens (plant and animal ones) protection from reactive oxygen species is also an aspect of their pathogenesity as many antibacterial protective mechanisms of eukaryotes represent generation of deadly oxygen and organic radicals.Many other stresses (starvation, pH, osmotic, temperature, etc..) lead also to oxidative stress.
Oxygen stress is a functional state which differs in dependence on an inducer and a type of reactive oxygen species being formed (See the diagram and the subsets of functional roles). Responses to H2O2, superoxide, singlet oxygen, peroxynitrite, etc will depend on a particular organism's protective responsive and enzymatic functions. Presence of one or more functional cassettes depends on environmental niche which a bacterium occupies and the probability of being a subject of the specific type of oxidative damage.
Presence of free Iron and free heme can be damaging to a cell, particularly in oxidative stress (See :Fenton reaction on the Diagram). Fe efflux and heme recycling are regulated by different Iron-dependent response pathways. Zn, oppositely plays a protective role. It is a part of catalytic centre of Metallotioneine and of other enzymes which can lose Zn in conditions of high nitric oxide or superoxide as well as modified by peroxinitrite.
Rubrerythrin (Rbr) is a nonheme iron protein that protects many air-sensitive bacteria against oxidative stress and reactive nitrogen species (within leukocyte secretory granules). The related clustering functions are included in the other related SS: 'Rubrerythrin'
We did not include glutathione transferases and other thiol-related functions here. They are supposed to be grouped in another SS, which will come up soon.
Because it is difficult to distinguish different response regulators this SS will be reviewed from time to time as new organisms and new gene clusters will populate the Seed database. If you have any suggestions on how to improve this SS please, do not hesitate to contact me (OlgaV@TheFig.info)
For more information, please check out the description and the additional notes tabs, below
|Diagram||Functional Roles||Subsystem Spreadsheet||Description||Additional Notes|