TY - JOUR
T1 - AP lyases and dRPases
T2 - Commonality of mechanism
AU - Piersen, Colleen E.
AU - McCullough, Amanda K.
AU - Lloyd, R. Stephen
N1 - Funding Information:
We thank the following investigators for providing us with homogeneous enzyme preparations: Drs. Samuel H. Wilson and Rajendra Prasad, β-pol; Drs. Ben Van Houten and Mike Yakes, Fpg; and Dr. Susan Lovett and Vincent Sutera, Rec J. Endo III and T4 endo V were purified by Bin Sun and Russ Carmical, respectively, in the Lloyd laboratory. This work was supported by National Institutes of Health grants ES04091 (RSL), ES06676 (RSL) and ES05780 (AKM). RSL Holds the Mary Gibbs Jones Distinguished Chair in Environmental Toxicology from the Houston Endowment.
PY - 2000/2/16
Y1 - 2000/2/16
N2 - Enzymes that release 5'-deoxyribose-5-phosphate (dRP) residues from preincised apurinic/apyrimidinic (AP) DNA have been collectively termed DNA deoxyribophosphodiesterases (dRPases), but they fall into two distinct categories: the hydrolytic dRPases and AP lyases. In order to resolve a number of conflicting reports in the dRPase literature, we examined two putative hydrolytic dRPases (Escherichia coli exonuclease I (exo I) and RecJ) and four AP lyases (E. coli 2,6-dihydroxy-5N-formamidopyrimidine (Fapy) DNA glycosylase (Fpg) and endonuclease III (endo III), bacteriophage T4 endonuclease V (endo V), and rat polymerase β (β-pol)) for their abilities to (i) excise dRP from preincised AP DNA and (ii) incise AP DNA. Although exo I and RecJ exhibited robust 3' to 5' and 5' to 3' exonucleolytic activities, respectively, on appropriate substrates, they failed to demonstrate detectable dRPase activity. All four AP lyases possessed both dRPase and traditional AP lyase activities, albeit to varying degrees. Moreover, as best illustrated with Fpg, AP lyase enzymes could be trapped on both preincised and unincised AP DNA using NaBH4 as the reducing agent. These results further support the assertion that the catalytic mechanism of the AP lyases, the β-elimination reaction, does proceed through an imine enzyme-DNA intermediate and that the active site residues responsible for dRP release must contain primary amines. Further, these data indicate a biological significance for the β-elimination reaction of DNA glycosylase/AP lyases in that they, in concert with hydrolytic AP endonucleases, can create appropriate gapped substrates for short patch base excision repair (BER) synthesis to occur efficiently. Copyright (C) 2000 Elsevier Science B.V.
AB - Enzymes that release 5'-deoxyribose-5-phosphate (dRP) residues from preincised apurinic/apyrimidinic (AP) DNA have been collectively termed DNA deoxyribophosphodiesterases (dRPases), but they fall into two distinct categories: the hydrolytic dRPases and AP lyases. In order to resolve a number of conflicting reports in the dRPase literature, we examined two putative hydrolytic dRPases (Escherichia coli exonuclease I (exo I) and RecJ) and four AP lyases (E. coli 2,6-dihydroxy-5N-formamidopyrimidine (Fapy) DNA glycosylase (Fpg) and endonuclease III (endo III), bacteriophage T4 endonuclease V (endo V), and rat polymerase β (β-pol)) for their abilities to (i) excise dRP from preincised AP DNA and (ii) incise AP DNA. Although exo I and RecJ exhibited robust 3' to 5' and 5' to 3' exonucleolytic activities, respectively, on appropriate substrates, they failed to demonstrate detectable dRPase activity. All four AP lyases possessed both dRPase and traditional AP lyase activities, albeit to varying degrees. Moreover, as best illustrated with Fpg, AP lyase enzymes could be trapped on both preincised and unincised AP DNA using NaBH4 as the reducing agent. These results further support the assertion that the catalytic mechanism of the AP lyases, the β-elimination reaction, does proceed through an imine enzyme-DNA intermediate and that the active site residues responsible for dRP release must contain primary amines. Further, these data indicate a biological significance for the β-elimination reaction of DNA glycosylase/AP lyases in that they, in concert with hydrolytic AP endonucleases, can create appropriate gapped substrates for short patch base excision repair (BER) synthesis to occur efficiently. Copyright (C) 2000 Elsevier Science B.V.
KW - AP lyase
KW - DNA repair
KW - Deoxyribophosphodiesterase
KW - dRPase
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U2 - 10.1016/S0921-8777(99)00054-3
DO - 10.1016/S0921-8777(99)00054-3
M3 - Article
C2 - 10677682
AN - SCOPUS:0033951831
SN - 0921-8777
VL - 459
SP - 43
EP - 53
JO - Mutation Research - DNA Repair
JF - Mutation Research - DNA Repair
IS - 1
ER -