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Gu S, Al-Hashimi HM. Direct Measurement of 8OG Syn-Anti Flips in Mutagenic 8OG·A and Long-Range Damage-Dependent Hoogsteen Breathing Dynamics Using 1H CEST NMR. J Phys Chem B 2024; 128:4087-4096. [PMID: 38644782 DOI: 10.1021/acs.jpcb.4c00316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Elucidating how damage impacts DNA dynamics is essential for understanding the mechanisms of damage recognition and repair. Many DNA lesions alter their propensities to form low-populated and short-lived conformational states. However, NMR methods to measure these dynamics require isotopic enrichment, which is difficult for damaged nucleotides. Here, we demonstrate the utility of the 1H chemical exchange saturation transfer (CEST) NMR experiment in measuring the dynamics of oxidatively damaged 8-oxoguanine (8OG) in the mutagenic 8OGsyn·Aanti mismatch. Using 8OG-H7 as an NMR probe of the damaged base, we directly measured 8OG syn-anti flips to form a lowly populated (pop. ∼ 5%) and short-lived (lifetime ∼50 ms) nonmutagenic 8OGanti·Aanti. These exchange parameters were in quantitative agreement with values from 13C off-resonance R1ρ and CEST on the labeled partner adenine. The Watson-Crick-like 8OGsyn·Aanti mismatch also rescued the kinetics of Hoogsteen motions at distant A-T base pairs, which the G·A mismatch had slowed down. The results lend further support for 8OGanti·Aanti as a minor conformational state of 8OG·A, reveal that 8OG damage can impact Hoogsteen dynamics at a distance, and demonstrate the utility of 1H CEST for measuring damage-dependent dynamics in unlabeled DNA.
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Affiliation(s)
- Stephanie Gu
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, United States
| | - Hashim M Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, United States
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Gu S, Al-Hashimi HM. Direct Measurement of 8OG syn-anti Flips in Mutagenic 8OG•A and Long-Range Damage-Dependent Hoogsteen Breathing Dynamics Using 1H CEST NMR. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.15.575532. [PMID: 38293035 PMCID: PMC10827055 DOI: 10.1101/2024.01.15.575532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Elucidating how damage impacts DNA dynamics is essential for understanding the mechanisms of damage recognition and repair. Many DNA lesions alter the propensities to form lowly-populated and short-lived conformational states. However, NMR methods to measure these dynamics require isotopic enrichment, which is difficult for damaged nucleotides. Here, we demonstrate the utility of the 1H chemical exchange saturation transfer (CEST) NMR experiment in measuring the dynamics of oxidatively damaged 8-oxoguanine (8OG) in the mutagenic 8OGsyn•Aanti mismatch. Using 8OG-H7 as an NMR probe of the damaged base, we directly measured 8OG syn-anti flips to form a lowly-populated (pop. ~ 5%) and short-lived (lifetime ~ 50 ms) non-mutagenic 8OGanti•Aanti. These exchange parameters were in quantitative agreement with values from 13C off-resonance R1ρ and CEST on a labeled partner adenine. The Watson-Crick-like 8OGsyn•Aanti mismatch also rescued the kinetics of Hoogsteen motions at distance A-T base pairs, which the G•A mismatch had slowed down. The results lend further support for 8OGanti•Aanti as a minor conformational state of 8OG•A, reveal that 8OG damage can impact Hoogsteen dynamics at a distance, and demonstrate the utility of 1H CEST for measuring damage-dependent dynamics in unlabeled DNA.
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Affiliation(s)
- Stephanie Gu
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Hashim M. Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
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Zhang Q, Shu J, Zhang Y, Xu Z, Yue J, Liu X, Xu B, Chen Z, Jiang W. Structures and esterolytic reactivity of novel binuclear copper(ii) complexes with reduced l-serine Schiff bases as mimic carboxylesterases. Dalton Trans 2020; 49:10261-10269. [PMID: 32672259 DOI: 10.1039/d0dt01823f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three novel binuclear copper(ii) complexes with reduced l-serine Schiff bases were synthesized and their structures were analyzed with single-crystal X-ray diffraction and DFT calculations. The crystal data revealed that all of these binuclear complexes are chiral. Both 5-halogenated (bromo- and chloro-) binuclear complexes exhibit right-handed helix structural character. Interestingly, the 5-methyl-containing analogue has a two-dimensional pore structure. In this paper, the esterolysis reactivity of the as-prepared complexes shows that in the hydrolysis of p-nitrophenyl acetate (PNPA) these three complexes provide 26, 18, 40-fold rate acceleration as compared to the spontaneous hydrolysis of PNPA at pH 7.0, respectively. Under selected conditions, in excess buffered aqueous solution a rate enhancement by three orders of magnitude was observed for the catalytic hydrolysis of another carboxylic ester, p-nitrophenyl picolinate (PNPP). These complexes efficiently promoted PNPP hydrolysis in a micellar solution of cetyltrimethylammonium bromide (CTAB), giving rise to a rate enhancement in excess of four orders of magnitude, which is approximately 2.0-3.2 times higher than that in the buffer.
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Affiliation(s)
- Qin Zhang
- School of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Sichuan Zigong 643000, P. R. China.
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de Faria RC, Vila-Nova LG, Bitar M, Resende BC, Arantes LS, Rebelato AB, Azevedo VAC, Franco GR, Machado CR, Santos LLD, de Oliveira Lopes D. Adenine Glycosylase MutY of Corynebacterium pseudotuberculosis presents the antimutator phenotype and evidences of glycosylase/AP lyase activity in vitro. INFECTION GENETICS AND EVOLUTION 2016; 44:318-329. [PMID: 27456281 DOI: 10.1016/j.meegid.2016.07.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/07/2016] [Accepted: 07/21/2016] [Indexed: 01/30/2023]
Abstract
Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis, a disease that predominantly affects small ruminants, causing significant economic losses worldwide. As a facultative intracellular pathogen, this bacterium is exposed to an environment rich in reactive oxygen species (ROS) within macrophages. To ensure its genetic stability, C. pseudotuberculosis relies on efficient DNA repair pathways for excision of oxidative damage such as 8-oxoguanine, a highly mutagenic lesion. MutY is an adenine glycosylase involved in adenine excision from 8-oxoG:A mismatches avoiding genome mutation incorporation. The purpose of this study was to characterize MutY protein from C. pseudotuberculosis and determine its involvement with DNA repair. In vivo functional complementation assay employing mutY gene deficient Escherichia coli transformed with CpmutY showed a 13.5-fold reduction in the rate of spontaneous mutation, compared to cells transformed with empty vector. Also, under oxidative stress conditions, CpMutY protein favored the growth of mutY deficient E. coli, relative to the same strain in the absence of CpMutY. To demonstrate the involvement of this enzyme in recognition and excision of 8-oxoguanine lesion, an in vitro assay was performed. CpMutY protein was capable of recognizing and excising 8-oxoG:A but not 8-oxoG:C presenting evidences of glycosylase/AP lyase activity in vitro. In silico structural characterization revealed the presence of preserved motifs related to the MutY activity on DNA repair, such as catalytic residues involved in glycosylase/AP lyase activity and structural DNA-binding elements, such as the HhH motif and the [4Fe-4S] cluster. The three-dimensional structure of CpMutY, generated by comparative modeling, exhibits a catalytic domain very similar to that of E. coli MutY. Taken together, these results indicate that the CpmutY encodes a functional protein homologous to MutY from E. coli and is involved in the prevention of mutations and the repair of oxidative DNA lesions.
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Affiliation(s)
- Rafael Cançado de Faria
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
| | - Liliane Gonçalves Vila-Nova
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
| | - Mainá Bitar
- Laboratory of Genetics and Biochemistry, Department of Biochemistry, ICB, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil.
| | - Bruno Carvalho Resende
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
| | - Larissa Sousa Arantes
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
| | - Arnaldo Basso Rebelato
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
| | - Vasco Ariston Carvalho Azevedo
- Laboratory of Cell and Molecular Genetics, Department of General Biology, ICB, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil.
| | - Glória Regina Franco
- Laboratory of Genetics and Biochemistry, Department of Biochemistry, ICB, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil.
| | - Carlos Renato Machado
- Laboratory of Genetics and Biochemistry, Department of Biochemistry, ICB, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil.
| | - Luciana Lara Dos Santos
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
| | - Débora de Oliveira Lopes
- Laboratory of Molecular Biology, Federal University of São João Del-Rei (CCO), Av. Sebastião Gonçalves Coelho, 400, Divinópolis, MG 35501-296, Brazil.
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Brooks SC, Adhikary S, Rubinson EH, Eichman BF. Recent advances in the structural mechanisms of DNA glycosylases. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:247-71. [PMID: 23076011 DOI: 10.1016/j.bbapap.2012.10.005] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/24/2012] [Accepted: 10/05/2012] [Indexed: 02/06/2023]
Abstract
DNA glycosylases safeguard the genome by locating and excising a diverse array of aberrant nucleobases created from oxidation, alkylation, and deamination of DNA. Since the discovery 28years ago that these enzymes employ a base flipping mechanism to trap their substrates, six different protein architectures have been identified to perform the same basic task. Work over the past several years has unraveled details for how the various DNA glycosylases survey DNA, detect damage within the duplex, select for the correct modification, and catalyze base excision. Here, we provide a broad overview of these latest advances in glycosylase mechanisms gleaned from structural enzymology, highlighting features common to all glycosylases as well as key differences that define their particular substrate specificities.
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Affiliation(s)
- Sonja C Brooks
- Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
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Robles AG, Reid K, Roy F, Fletcher HM. Porphyromonas gingivalis mutY is involved in the repair of oxidative stress-induced DNA mispairing. Mol Oral Microbiol 2011; 26:175-86. [PMID: 21545695 DOI: 10.1111/j.2041-1014.2011.00605.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ability for DNA mismatch repair, after oxidative stress-induced DNA damage, is critical for the persistence of Porphyromonas gingivalis in the inflammatory environment of the periodontal pocket. Our previous report demonstrated that, in contrast to other organisms, the repair of oxidative stress-induced DNA damage involving 8-oxo-7,8-dihydroguanine (8-oxoG) may occur by a yet-to-be described mechanism in P. gingivalis. 8-oxoG does not block DNA replication; rather, it mispairs with adenine, which can be repaired by the MutY glycosylase. To determine the function of the P. gingivalis MutY homologue in DNA repair, it was insertionally inactivated using the ermF-ermAM antibiotic cassette and used to create a mutY-deficient mutant (FLL147) by allelic exchange mutagenesis. FLL147 had an increased rate of spontaneous mutation and was more sensitive to hydrogen peroxide compared with the wild-type W83 strain. DNA oligomers containing a site-specific 8-oxoG:A mispair was repaired similarly in both the P. gingivalis mutY-defective mutant and wild-type strains. The P. gingivalis mutY homologue was shown to complement the mutY mutation in Escherichia coli. In a gel mobility shift assay, the purified recombinant MutY is able to bind an oligo containing an 8-oxoG:A mispair. Taken together, MutY may play the expected role in oxidative stress resistance in P. gingivalis. However, there may exist other redundant mechanism(s) for the removal of 8-oxoG:A mismatch in this organism.
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Affiliation(s)
- A G Robles
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
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