UvrAB

UvrAB is a protein complex involved in DNA repair mechanisms in bacteria, primarily functioning in nucleotide excision repair (NER). This vital process allows bacteria to correct a wide range of DNA damages caused by ultraviolet (UV) light, chemical mutagens, and other environmental factors. The UvrAB complex consists of two proteins: UvrA and UvrB, which work together to recognize and initiate the repair process.

UvrA is responsible for scanning the DNA for distortions caused by lesions. Once damage is detected, UvrA interacts with UvrB, facilitating the formation of the UvrAB complex at the site of the lesion. UvrA then dissociates, allowing UvrB to bind more tightly to the damaged DNA. UvrB acts as a helicase, unwinding the DNA around the lesion to enable the excision of damaged nucleotides.

The UvrAB complex plays an essential role in maintaining genomic integrity in bacteria. Its activity is complemented by subsequent proteins, such as UvrC, which makes dual incisions around the lesion, and UvrD, a helicase that removes the damaged oligonucleotide. The integrity of this repair pathway is critical for bacterial survival under genotoxic stress.

Mutations in the uvrAB genes can lead to increased sensitivity to UV radiation and other DNA-damaging agents, often resulting in a mutator phenotype. These mutations are also used in molecular biology experiments to generate bacterial strains deficient in nucleotide excision repair, facilitating research into DNA repair mechanisms.

Overall, uvrAB is fundamental to bacterial DNA repair, aiding in the preservation of genetic information and cellular health in fluctuating environmental conditions.