Final answer:
The Prokaryotic SOS global DNA damage response pathway is a bacterial mechanism activated to repair or tolerate DNA damage, which can include error-prone processes leading to mutations. In contrast, eukaryotic cells, like human cells, use the p53 and p21 proteins to manage DNA damage during the cell cycle. Prokaryotes also have the CRISPR/Cas system as an adaptive immune response against viruses.
Step-by-step explanation:
The Prokaryotic SOS global DNA damage response pathway is an emergency response mechanism activated in bacteria, such as E. coli, when DNA damage is detected. The SOS pathway involves the induction of several genes whose products help in DNA repair, error-prone DNA replication, or cell cycle arrest to allow damage repair before division. However, it can also lead to an increased mutation rate due to the activation of error-prone polymerases.
For example, in E. coli, when DNA damage is extensive, the RecA protein stimulates the self-cleavage of the LexA repressor, leading to the derepression of the SOS genes allowing for DNA repair processes to occur. On the other hand, eukaryotes, like human cells, use other proteins, such as p53 and p21, to halt the cell cycle at the G1 checkpoint to address DNA damage. In eukaryotes, if the DNA damage cannot be repaired, proteins like p53 can initiate apoptosis to prevent the proliferation of cells with compromised genetic integrity.
While discussing bacterial DNA damage response and immunity against viruses, the CRISPR/Cas system is another mechanism that prokaryotes use, which provides an adaptive immune response against invading viral DNA by creating a memory of the damage through the insertion of viral DNA segments into CRISPR regions within bacterial genomes.