Sites of Termination of<i>in Vitro</i>DNA Synthesis on Psoralen Phototreated Single-stranded Templates

Piette, Jacques; Hearst, John E.

doi:10.1080/09553008514551381

Cited by 19 publications

(10 citation statements)

References 26 publications

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“…Binding to single strands occurs to a much smaller extent,17 with no preference for the sequence surrounding the reactive thymine 18. Several studies agree that the 5’-TA site is more reactive than the 5’-AT site,11,15,16,19-24 and that repeated T-A sequences are hot spots for reaction due to the increased number of potential binding sites 15,24-26…”

Section: Introductionmentioning

confidence: 99%

Rapid characterization of cross-links, mono-adducts, and non-covalent binding of psoralens to deoxyoligonucleotides by LC-UV/ESI-MS and IRMPD mass spectrometry

Smith

Brodbelt

2010

Analyst

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SummaryUpon UV photoactivation, psoralen analogs form covalent mono-adducts and cross-links with DNA at thymine residues. Electrospray ionization mass spectrometric analysis allowed rapid and efficient determination of the reaction percentages of each psoralen analog with DNA duplexes containing different binding sites after exposure to UV irradiation. The distribution of cross-linked products and mono-adducts was monitored by both LC-UV and IRMPD-MS methods with the highest ratio of cross-linked products to mono-adducts obtained for 8-methoxypsoralen (8-MOP), psoralen (P), and 5-methoxypsoralen (5-MOP). Reactions at 5'-TA sites were favored over 5'-AT sites, and duplexes containing two and three binding sites showed extensive binding by the psoralens. 4'-aminomethyl-4,5',8-trimethylpsoralen (AMP) bound non-selectively via non-covalent interactions and was the only psoralen analog to show significant binding in the absence of UV irradiation. 8-MOP binding displayed the greatest sequence selectivity among the psoralen analogs. The sites of interstrand cross-linking were determined by fragmentation of the duplex/psoralen complexes by infrared multiphoton dissociation (IRMPD), which produced cross-linked product ions containing an intact single strand, the psoralen analog, and either a w n or a n -B portion of the complementary strand. IRMPD of DNA/AMP complexes after UV irradiation also produced high abundances of the intact single strands with the AMP ligand attached, products indicative of a significant population of mono-adducts.

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Section: Introductionmentioning

confidence: 99%

Rapid characterization of cross-links, mono-adducts, and non-covalent binding of psoralens to deoxyoligonucleotides by LC-UV/ESI-MS and IRMPD mass spectrometry

Smith

Brodbelt

2010

Analyst

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“…It has been shown that psoralen interstrand diadducts block replication by E. coli DNA polymerase I, whereas psoralen monoadducts act as kinetic attenuators when located on the template strand and have no effect when located on the nick translated strand (26)(27). However, psoralen monoadducts on a single-stranded DNA template terninate DNA synthesis by E. coli DNA polymerase I large fragment, T4 DNA polymerase, and AMV reverse transcriptase (28).…”

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confidence: 99%

The effects of covalent additions of a psoralen on transcription byE. coliRNA polymerase

1987

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Synthetic DNA substrates containing a site-specifically engineered psoralen monoadduct or diadduct were used to characterize the response of the E. coli RNA polymerase elongation complex to these lesions. The psoralen derivative HMT (4'-hydroxymethyl-4,5', 8-trimethylpsoralen) was site specifically placed into two synthetic double-stranded DNA fragments each of which contained an E. coli RNA polymerase promoter at one end. The HMT molecule was attached to the middle of the DNA fragments as either a furan-side monoadduct or an interstrand diadduct. Transcription off the HMT crosslinked DNA templates showed that E. coli RNA polymerase terminated at the HMT diadduct site, i. e., one nucleotide before the modified thymidine residue on the template strand. The furan-side monoadduct when on the template strand also blocked transcription by the polymerase. However, no effect on transcription was observed when the monoadduct was located on the non-template strand.

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“…(11,12) found that UvrABC makes a dual incision only on the strand that interacts with the furan moiety of psoralen and does not cause a DSB. Moreover, while Pitte and Hearst (33) found that a dT-psoralen-dT ICL causes a 46.5° kink, Rink et al . (16) found that both MC-mono-dG and ICL dG-MC-dG lesions do not cause DNA bending.…”

Section: Discussionmentioning

confidence: 99%

Repair of mitomycin C mono- and interstrand cross-linked DNA adducts by UvrABC: a new model

Weng

Zheng

Jasti

et al. 2010

Nucleic Acids Research

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Mitomycin C induces both MC-mono-dG and cross-linked dG-adducts in vivo. Interstrand cross-linked (ICL) dG-MC-dG-DNA adducts can prevent strand separation. In Escherichia coli cells, UvrABC repairs ICL lesions that cause DNA bending. The mechanisms and consequences of NER of ICL dG-MC-dG lesions that do not induce DNA bending remain unclear. Using DNA fragments containing a MC-mono-dG or an ICL dG-MC-dG adduct, we found (i) UvrABC incises only at the strand containing MC-mono-dG adducts; (ii) UvrABC makes three types of incisions on an ICL dG-MC-dG adduct: type 1, a single 5′ incision on 1 strand and a 3′ incision on the other; type 2, dual incisions on 1 strand and a single incision on the other; and type 3, dual incisions on both strands; and (iii) the cutting kinetics of type 3 is significantly faster than type 1 and type 2, and all of 3 types of cutting result in producing DSB. We found that UvrA, UvrA + UvrB and UvrA + UvrB + UvrC bind to MC-modified DNA specifically, and we did not detect any UvrB- and UvrB + UvrC–DNA complexes. Our findings challenge the current UvrABC incision model. We propose that DSBs resulted from NER of ICL dG-MC-dG adducts contribute to MC antitumor activity and mutations.

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Sites of Termination ofin VitroDNA Synthesis on Psoralen Phototreated Single-stranded Templates

Cited by 19 publications

References 26 publications

Rapid characterization of cross-links, mono-adducts, and non-covalent binding of psoralens to deoxyoligonucleotides by LC-UV/ESI-MS and IRMPD mass spectrometry

Rapid characterization of cross-links, mono-adducts, and non-covalent binding of psoralens to deoxyoligonucleotides by LC-UV/ESI-MS and IRMPD mass spectrometry

The effects of covalent additions of a psoralen on transcription byE. coliRNA polymerase

Repair of mitomycin C mono- and interstrand cross-linked DNA adducts by UvrABC: a new model

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