TY - JOUR
T1 - Base analog N6-hydroxylaminopurine mutagenesis in Escherichia coli
T2 - Genetic control and molecular specificity
AU - Pavlov, Youri I.
AU - Suslov, Valentin V.
AU - Shcherbakova, Polina V.
AU - Kunkel, Thomas A.
AU - Ono, Akira
AU - Matsuda, Akira
AU - Schaaper, Roel M.
N1 - Funding Information:
We would like to thank Drs. K. Bebenek and D. Gordenin for helpful suggestions during this work and for critically reading the manuscript. The re-searchd escribedin this publication was made possible in part by grant #JDHlOO from the International Science Foundation and the Russian Government to Y.I.P. This research was also supported in part by Russian Program ‘Frontiers in Genetics’ grants No. 12-5 and No. 25 and the ‘Russian Fund for Fundamental Scientific Research’ grant No. 9S-04-1I 5831 to Y.I.P.
PY - 1996/10/25
Y1 - 1996/10/25
N2 - We have studied the molecular specificity of the base analog N6-hydroxylaminopurine (HAP) in the E coli lacI gene, as well as the effects of mutations in DNA repair and replication genes on HAP mutagenesis. HAP induced base substitutions of the two transition types (A·T → G·C → and G·C → A·T) at equal frequency. This bi-directional transition specificity is consistent with in vitro primer extension experiments with the Klenow fragment of DNA polymerase I in which we observed that either dTTP or dCTP were incorporated opposite HAP in an oligonucleotide template. The spectrum of HAP-induced transitions was different from the spontaneous transitions in either a wild-type or a mismatch-repair-defective (mutL) strain. Mutations in genes controlling excision repair, exonucleolytic proofreading, mismatch correction, error-prone (SOS) repair and 8-oxo-guanine repair did not affect HAP-induced mutagenesis substantially. However, an extensive deletion of several genes in the uvrB-bio region conferred supersensitivity to the lethal and mutagenic effects of HAP, perhaps due to an effect on HAP metabolism. dnaE antimutator alleles reduced HAP-forward mutagenicity in allele-specific manner: dnaE911 reduced it several fold, while dnaE915 abolished it almost completely. The results obtained are consistent with the idea that HAP is mutagenic in E. coli via a pathway generating replication errors.
AB - We have studied the molecular specificity of the base analog N6-hydroxylaminopurine (HAP) in the E coli lacI gene, as well as the effects of mutations in DNA repair and replication genes on HAP mutagenesis. HAP induced base substitutions of the two transition types (A·T → G·C → and G·C → A·T) at equal frequency. This bi-directional transition specificity is consistent with in vitro primer extension experiments with the Klenow fragment of DNA polymerase I in which we observed that either dTTP or dCTP were incorporated opposite HAP in an oligonucleotide template. The spectrum of HAP-induced transitions was different from the spontaneous transitions in either a wild-type or a mismatch-repair-defective (mutL) strain. Mutations in genes controlling excision repair, exonucleolytic proofreading, mismatch correction, error-prone (SOS) repair and 8-oxo-guanine repair did not affect HAP-induced mutagenesis substantially. However, an extensive deletion of several genes in the uvrB-bio region conferred supersensitivity to the lethal and mutagenic effects of HAP, perhaps due to an effect on HAP metabolism. dnaE antimutator alleles reduced HAP-forward mutagenicity in allele-specific manner: dnaE911 reduced it several fold, while dnaE915 abolished it almost completely. The results obtained are consistent with the idea that HAP is mutagenic in E. coli via a pathway generating replication errors.
KW - Antimutator DNA polymerase
KW - Base analog N-hydroxylaminopurine
KW - Escherichia coli
KW - Mutagenic specificity
KW - Δ(uvrB-bio) deletion
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U2 - 10.1016/0027-5107(96)00060-7
DO - 10.1016/0027-5107(96)00060-7
M3 - Article
C2 - 8876675
AN - SCOPUS:0030601717
SN - 0027-5107
VL - 357
SP - 1
EP - 15
JO - Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
JF - Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
IS - 1-2
ER -