UvrABC

Very recently, it has been observed that E. coli produces UvrABC excision repair proteins, and that the UvrAB complex binds to the convex side of a cisplatin-induced kink in DNA (205) It would be of great interest to study the similarities between this complex and the DRP protein mentioned above. 

Sancar, A. Rupp, W.D. (1983). A novel repair enzyme UVRABC excision nuclease of Escherichia coli cuts a DNA strand on both sides of the damaged region. Cell 33, 249-260. 

Four enzymes are directly involved. They are the UvrABC endonuclease, helicase, DNA polymerase I, and DNA ligase. The first cleaves the DNA strand on both sides of the pyrimidine dimer. The second enzyme removes the single-strand nucleotide segment containing the pyrimidine dimer. DNA polymerase I fills the gap with new DNA, and the nick is sealed by DNA ligase. 

Van Houten, B., Croteau, D. L., Della Vecchia, M. J., Wang, H., and Kisker, C. Close-fitting sleeves DNA damage recognition by the UvrABC nuclease system. Mutat. Res. 577, 92-117, 2005. 

One of the best-understood examples of nucleotide-excision repair is the excision of a pyrimidine dimer. Three enzymatic activities are essential for this repair process in E. coli (Figure 27.49). First, an enzyme complex consisting of the proteins encoded by the uvrABC genes detects the distortion produced by the pyrimidine dimer. A specific uvrABC... 

Excision of a 12-nucleotide fragment by uvrABC exci nuclease... 

The solution structures of DNA duplexes containing the mutagenic lesions of benzo [a] pyrene-dtrihydroxybenz[a] anthracene, aminopyrene-dG, aminofluorene-dG and malondialdehyde-dG derivatives have been reported. In each case the lesion was shown to intercalate into the duplex causing only minimal disruption to the duplex structure. These structures have been used to study the nucleotide excision repair (NER) by the UvrABC nuclease system from E. coli of the bulky purine lesions. ... 

Dependence of Nucleotide Excision Repair by E. coli UvrABC Proteins on Adduct Conformation... 

Figure 10.4 Incision efficiency (% DNA incision/min) of (a) AF versus FAF on the same 12mer (5 -CTTCTAGG CCTC-3 ) sequence and (b) the -AG N- and -CG N- sequences versus percentage S-conformer by E. coli UvrABC nuclease [55].

Mekhovich, O., Tang, M., and Romano, LJ. (1998) Rate of incision of N-acetyl-2-aminofluorene and N-2-aminofluorene adducts by UvrABC nuclease is... 

B., and Geadntov, N.E. (2007) Sequence context- and temperature-dependent nucleotide exdsion repair of a benzojo] pyrene diol epoxide-guanine DNA addud catalyzed by thermophilic UvrABC proteins. Biochemistry, 46, 7006-7015. 

NER in bacteria involves only three proteins to carry out the complete process of damage recognition and excision UvrA, UvrB, and UvrC. Owing to its relative simplicity, the UvrABC system has been studied extensively, particularly in E. coli, and serves as a model system for NER [20, 21]. 

The sequence-dependent trend is conserved in the prokaryotic UvrABC system, in which the NER dual-incision efficiency is around 2.4-fold higher for the same 10S (+)-trans-anti-B[a]P-N2-dG adduct in the TG T case than the CG C-II case [124]. Similarly, the G6 G7 duplex is incised more efficiently by a factor of around... 

Mechanism of action of the Escherichia coli UvrABC nuclease clues to the damage recognition problem. Bioessays, 15, 51-59. 

Use of UvrABC nuclease to quantify benzojajpyrene diol epoxide-DNA adduct formation at methylated versus unmethylated CpG sites in the p53 gene. Carcinogenesis, 20, 1085-1089. 

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