Endonuclease III

D Ham, C. Romieu, A. Jaquinod, M. Gasparutto, D. Cadet, J. Excision of 5,6-dihydroxy-5,6-dihydrothymine, 5,6-dihydrothymine, and 5- hydroxycytosine from defined sequence oligonucleotides by Escherichia coli endonuclease III and Fpg proteins Kinetic and mechanistic aspects. Biochemistry 1999, 38, 3335-3344. 

Utilising a reversion assay in Salmonella enterica, Prieto et al reported an increased frequency of point mutations following bile-salt exposure. Mutations were predominantly nucleotide substitutions (GC to AT transitions) and -1 frameshift mutations.The frameshifts were dependent on SOS induction and linked to the activity of DinB polymerase (Pol IV). The authors proposed that the GC to AT transitions stimulated by bile, could have arisen from oxidative processes giving rise to oxidised cytosine residues. Consistent with this hypothesis, the authors demonstrated that strains of S. enterica-lacking enzymes required for base-excision repair (endonuclease III and exonuclease IV) and the removal of oxidised bases, demonstrated increased bile-acid sensitivity compared with competent strains. In another study using E. coli, resistance to the DNA-damaging effects of bile was associated with Dam-directed mismatch repair, a pathway also involved with the repair of oxidative DNA lesions. ... 

This enzyme (also known as DNA-(apurmic or apyrimid-inic site) lyase, AP endonuclease class I, E. coli endonuclease III, Phage-T4 UV endonuclease, and Micrococcus luteus UV endonuclease) catalyzes the cleavage of the phosphodiester bond in a lyase-type reaction, not hydro-... 

Molecular Graphics Images by Michael Pique using software by Yng Chen, Michael Connolly, Michael Carson, Alex Shah, and AVS, Inc. Endonuclease III by Kuo,... 

This type of reaction inhibits the repair by endonuclease III from E. coli, and Lys-120 is responsible for this cross-linking reaction. Under the conditions of these experiments, the cross-linking efficiency is 20%. It is expected that such cross-linking reactions are more general and that more examples will be detected. 

Campbell JM, Schulte-Frohlinde D, von Sonntag C (1974) Quantum yields in the UV photolysis of 5-bromo-uracil in the presence of hydrogen donors. Photochem Photobiol 20 465-467 Chapman JD (1984) The cellular basis of radiotherapeutic response. Radiat Phys Chem 24 283-291 Chatterjee M, Mah SC, Tullius TD, Townsend CA (1995) Role of the aryl iodide in the sequence-selective cleavage of DNA by calicheamicin. Importance of thermodynamic binding vs kinetic activation process. J Am Chem Soc 117 8074-8082 Chaudry MA, Weinfeld M (1995) The action of Escherichia coli endonuclease III on multiply damaged sites in DNA. J Mol Biol 249 914-922... 

E. coli Nth protein (endonuclease III) Oxidized pyrimidines Ring-saturated or fragmented Thy residues, e.g. F Thy, Tg, 5-hydroxy-5-methylhydantoine, urea, DNA damaged at Gua, some abasic sites... 

E. coli endonuclease III is the prototype of DNA repair enzymes that contain a [4Fe-4S] cluster [20], The cluster has four Cys ligands and does not appear to be involved in the catalysis. It may have a structural, in particular, a charge-compensating, role [21,22],... 

NTH1" Endonuclease III Removes ring-saturated of fragmented pyrimidines... 

Katafuchi, A., Nakano, T., Masaoka, A., Terato, H., Iwai, S., Hanaoka, F., and Ide, H. (2004) Differential specificity of human and Escherichia coli endonuclease III and VIII homologues for oxidative base lesions. J. Biol. Chem., 279,14464-14471. 

Hashimoto, M., Greenberg, M.M., Row, Y.W., Hwang, J.T., and Cunningham, R.P. (2001) The 2-deoxyribonolactone lesion produced in DNA by neocarzi-nostatin and other damaging agents forms cross-links with the base-excision repair enzyme endonuclease III./. Am. Chem. Soc., 123, 3161-3162. 

The first suggestion that the strand cleavage reaction catalyzed endonuclease III from E. coli, UV endonuclease V from bacteriophage T4, and UV endonuclease from Micrococcus luteus did not proceed by a hydrolytic mechanism was that the sugar-phosphate end could not be removed by the action of the 3 5 ... 

We have directly identified the sugar product of the strand cleavage reaction catalyzed by endonuclease III and UV endonuclease V as the trans-a,/3-unsaturated aldehyde obtained by elimination of the 3 -phosphate 108, 109)-, with the determination that these endonucleases stereospecifically abstract the 2-pro-S hydrogen, the stereochemical course of the /3-elimination reaction is syn... 

Fig. 14. Stereochemical course of the j3-elimination reaction catalyzed by endonuclease V from bacteriophage T4 and by endonuclease III from Escherichia coli. From Ref. 108.

Fpg + endonuclease III sensitive sites 500 human lymphoblast cells 250 kv X-rays [56]... 

---