Most of the information about stress response in prokaryotes comes from
studies in bacteria. Bacteria developed a set of measures to maintain homeostasis in
unstable environments. In response to a particular stress, bacteria switch their
transcription to an alternative mode that better serves survival in the changed
environment. They do it by using alternative sigma subunits of RNA polymerase
(RNAP). Some sigma factors induce a transcription switch to a particular program that
adjusts bacteria to specific stress, such as heat. Other sigma factors are responsible for
the general stress response that protects the bacteria from various stresses. In addition
to alternative transcriptional modes, bacteria use other mechanisms to cope with stress
including DNA damage stress response and programmed cell death in response to
severe stress.
Keywords: Bacteria, Cold shock response, Envelope stress, General stress
response, Heat shock response, (p)ppGpp, RNA thermometer, Stress, Sigma
factor, Toxin-antitoxin.
