UV PHOTO ACTIVATION REPAIR PATCH
UV PHOTO ACTIVATION REPAIR ACTIVATOR

After DNA repair, the RecA protein loses its efficiency to cause proteolysis, and the LexA protein will again bind to the SOS operator or switch off the SOS system.Р”Р„n SOS system always switches off when a DNA is healthy.

Inactivation of LexA protein activates the inducer proteins that repair the DNA damage but alters the DNA sequence.

Thus, a LexA protein could not bind with the SOS operator.

The formation of RecA protease causes autocatalytic proteolysis of LexA repressor protein.

When RecA interacts with the repressor protein, it converts into RecA protease.

Then, a LexA repressor comes in contact with the nucleoprotein filament assembled by the RecA protein.

On binding with the single stranded DNA fragments, RecA forms a filament-likeР’В structure around the DNA.

A RecA protein specifically binds to the single stranded DNA.

It floats in the vicinity of the cell in search of any damage in the DNA.

In case of excessive DNA damage, stress conditions etc., a cell responds by activating signal or RecA protein.

The mechanism of SOS repair is a complex cellular process mediated by the organism itself. It functions as an inhibitor of cell division It functions to bypass the lesion site of DNA and leads to alter the normal sequence of DNA Repairs recombinant DNA damage and gaps between double stranded DNA It functions to bypass the lesion site of DNA and leads to mutagenesis

UV PHOTO ACTIVATION REPAIR PATCH

Repairs cross-links, Me-directed mismatches, double stranded gaps and short patch nucleotide damage Repairs short patch nucleotide damage, cross-links and long patch nucleotide damage Inducer proteins: They are encoded by SOS-box genes that can activate the inducer proteins relative to the type of DNA damage.The repressor binds to the operator and causes inactivation or repression of the SOS system. Repressor protein: It is encoded by the РІР‚Сљ LexAРІР‚Сњ gene, which causes the inactivation of inducer proteins.Regulator protein: It is encoded by the РІР‚Сљ RecAРІР‚Сњ gene, whose function is to activate the repressed SOS system by inhibiting the binding of LexA to the SOS operator.

UV PHOTO ACTIVATION REPAIR ACTIVATOR

RecA acts as an activator of SOS genes in the SOS system, which causes proteolysis of the repressor protein and allows the SOS genes expression into different DNA repairing inducer proteins.Р”Р„n SOS system composed of the following components: The binding will repress the activity of SOS genes.Р”В«ut in mutated DNA, the inactivation of LexA repressor becomes necessary to induce the expression of SOS genes. LexA acts as a repressor protein that binds to the particular site of DNA or SOS box. Thus, there should be some controller that must control the expression of such genes. In normal DNA, a bacterial cell does not need DNA repair genes to be activated. It does not repair the DNA damage completely but provides tolerance ability to the affected organism. The SOS system remains repressed until the conversion of RecA protein into RecA protease. SOS repair refers to the DNA repair system, which uses RecA regulatory protein to inhibit the repressorРІР‚в„ўs activity and activate the SOS inducer genes to recover the DNA damage. In this context, we will discuss the definition, elements, principle of SOS repair along with the mechanism of SOS inactivation and activation. SOS repair system is an error-prone mechanism, as it works without a DNA template. РІР‚Сљ SOS response systemРІР‚Сњ refers to the mechanism in which an organism initiates the production of activator protein (RecA), which results in the dissociation of LexA repressor and activates the SOS inducer proteins.

Uv photo activation repair