Sammelbandbeitrag

Erschienen in: Regulatory RNAs in Prokaryotes

Herausgeberliste: Hess, WR; Marchfelder, A

Jahr der Veröffentlichung: 2011

Seiten: 1-14

ISBN: 978-3-7091-0217-6

eISBN: 978-3-7091-0218-3

DOI Link: https://doi.org/10.1007/978-3-7091-0218-3_1

Abstract: 

Most bacteria have to cope with frequent changes in their environment,
which generate unfavourable conditions for growth and survival. They
have evolved successful strategies as a response to these stresses.
Oxidative stress is a stress factor, which is critical in most bacterial
habitats and has been defined as an imbalance between pro-oxidants and
anti-oxidants in the cell (Storz and Zheng, 2000). Pro-oxidants are
mostly reactive oxygen species (ROS) that oxidize proteins, nucleic
acids and lipids and thus lead to harmful damage to the cell (Imlay,
2003). Anti-oxidants are cellular components countering these damaging
effects: i) enzymes or molecules which remove ROS like peroxidases,
superoxide dismutase, thioredoxin or glutathione, ii) proteins that
repair the damages like endo- and exonucleases or photolyases, and iii)
sensors and regulators necessary to mount the response to oxidative
stress like OxyR or SoxRS of E. coli.
ROS are generated from the ground state (triplet state) of molecular
oxygen when less than four electrons are transferred to one O₂
molecule resulting in partially reduced forms of oxygen (Imlay, 2003).
Such reactions are e. g. catalyzed by respiratory enzymes and lead to
the accumulation of hydrogen peroxide (H₂O₂), superoxide (O₂ ⁻) and hydroxyl radicals (OH^·).
But ROS are also produced by exposure of cells to metals, redox-active
drugs or radiation. Plants as well as animals produce ROS as a defence
against pathogens. In addition to electron transfer reactions, a spin
conversion of one electron of the oxygen molecule can generate the
reactive singlet oxygen (¹O₂). This reaction
occurs in the combined presence of light and a photosensitizer. In
nature, porphyrins (chlorophylls or protoporphyrin) and humic acids can
function as photosensitizers.

Harvard-Zitierstil: Berghoff, B. and Klug, G. (2011) Small RNAs with a role in the oxidative stress response of bacteria, in Hess, W. and Marchfelder, A. (eds.) Regulatory RNAs in Prokaryotes. Wien: Springer, pp. 1-14. https://doi.org/10.1007/978-3-7091-0218-3_1

APA-Zitierstil: Berghoff, B., & Klug, G. (2011). Small RNAs with a role in the oxidative stress response of bacteria. In Hess, W., & Marchfelder, A. (Eds.), Regulatory RNAs in Prokaryotes (pp. 1-14). Springer. https://doi.org/10.1007/978-3-7091-0218-3_1