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Kamat A, Tran NT, Sharda M, Sontakke N, Le TBK, Badrinarayanan A. Widespread prevalence of a methylation-dependent switch to activate an essential DNA damage response in bacteria. PLoS Biol 2024; 22:e3002540. [PMID: 38466718 PMCID: PMC10957082 DOI: 10.1371/journal.pbio.3002540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 03/21/2024] [Accepted: 02/06/2024] [Indexed: 03/13/2024] Open
Abstract
DNA methylation plays central roles in diverse cellular processes, ranging from error-correction during replication to regulation of bacterial defense mechanisms. Nevertheless, certain aberrant methylation modifications can have lethal consequences. The mechanisms by which bacteria detect and respond to such damage remain incompletely understood. Here, we discover a highly conserved but previously uncharacterized transcription factor (Cada2), which orchestrates a methylation-dependent adaptive response in Caulobacter. This response operates independently of the SOS response, governs the expression of genes crucial for direct repair, and is essential for surviving methylation-induced damage. Our molecular investigation of Cada2 reveals a cysteine methylation-dependent posttranslational modification (PTM) and mode of action distinct from its Escherichia coli counterpart, a trait conserved across all bacteria harboring a Cada2-like homolog instead. Extending across the bacterial kingdom, our findings support the notion of divergence and coevolution of adaptive response transcription factors and their corresponding sequence-specific DNA motifs. Despite this diversity, the ubiquitous prevalence of adaptive response regulators underscores the significance of a transcriptional switch, mediated by methylation PTM, in driving a specific and essential bacterial DNA damage response.
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Affiliation(s)
- Aditya Kamat
- National Centre for Biological Sciences (TIFR), Bengaluru, India
| | - Ngat T. Tran
- John Innes Centre, Department of Molecular Microbiology, Colney Lane, Norwich, United Kingdom
| | - Mohak Sharda
- National Centre for Biological Sciences (TIFR), Bengaluru, India
| | - Neha Sontakke
- National Centre for Biological Sciences (TIFR), Bengaluru, India
| | - Tung B. K. Le
- John Innes Centre, Department of Molecular Microbiology, Colney Lane, Norwich, United Kingdom
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2
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Fang Q. The Versatile Attributes of MGMT: Its Repair Mechanism, Crosstalk with Other DNA Repair Pathways, and Its Role in Cancer. Cancers (Basel) 2024; 16:331. [PMID: 38254819 PMCID: PMC10814553 DOI: 10.3390/cancers16020331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
O6-methylguanine-DNA methyltransferase (MGMT or AGT) is a DNA repair protein with the capability to remove alkyl groups from O6-AlkylG adducts. Moreover, MGMT plays a crucial role in repairing DNA damage induced by methylating agents like temozolomide and chloroethylating agents such as carmustine, and thereby contributes to chemotherapeutic resistance when these agents are used. This review delves into the structural roles and repair mechanisms of MGMT, with emphasis on the potential structural and functional roles of the N-terminal domain of MGMT. It also explores the development of cancer therapeutic strategies that target MGMT. Finally, it discusses the intriguing crosstalk between MGMT and other DNA repair pathways.
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Affiliation(s)
- Qingming Fang
- Department of Biochemistry and Structural Biology, Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX 78229, USA
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3
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Tessmer I, Margison GP. The DNA Alkyltransferase Family of DNA Repair Proteins: Common Mechanisms, Diverse Functions. Int J Mol Sci 2023; 25:463. [PMID: 38203633 PMCID: PMC10779285 DOI: 10.3390/ijms25010463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
DNA alkyltransferase and alkyltransferase-like family proteins are responsible for the repair of highly mutagenic and cytotoxic O6-alkylguanine and O4-alkylthymine bases in DNA. Their mechanism involves binding to the damaged DNA and flipping the base out of the DNA helix into the active site pocket in the protein. Alkyltransferases then directly and irreversibly transfer the alkyl group from the base to the active site cysteine residue. In contrast, alkyltransferase-like proteins recruit nucleotide excision repair components for O6-alkylguanine elimination. One or more of these proteins are found in all kingdoms of life, and where this has been determined, their overall DNA repair mechanism is strictly conserved between organisms. Nevertheless, between species, subtle as well as more extensive differences that affect target lesion preferences and/or introduce additional protein functions have evolved. Examining these differences and their functional consequences is intricately entwined with understanding the details of their DNA repair mechanism(s) and their biological roles. In this review, we will present and discuss various aspects of the current status of knowledge on this intriguing protein family.
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Affiliation(s)
- Ingrid Tessmer
- Rudolf Virchow Center, University of Würzburg, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany
| | - Geoffrey P. Margison
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
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4
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Kamat A, Badrinarayanan A. SOS-independent bacterial DNA damage responses: diverse mechanisms, unifying function. Curr Opin Microbiol 2023; 73:102323. [PMID: 37148591 DOI: 10.1016/j.mib.2023.102323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/23/2023] [Accepted: 04/06/2023] [Indexed: 05/08/2023]
Abstract
Cells across domains of life have dedicated pathways to sense and respond to DNA damage. These responses are broadly termed as DNA damage responses (DDRs). In bacteria, the best studied DDR is the Save our Soul (SOS) response. More recently, several SOS-independent DDRs have also been discovered. Studies further report diversity in the types of repair proteins present across bacterial species as well as differences in their mechanisms of action. Although the primary function of DDRs is preservation of genome integrity, the diverse organization, conservation, and function of bacterial DDRs raises important questions about how genome error correction mechanisms could influence or be influenced by the genomes that encode them. In this review, we discuss recent insights on three SOS-independent bacterial DDRs. We consider open questions in our understanding of how diversity in response and repair mechanisms is generated, and how action of these pathways is regulated in cells to ensure maintenance of genome integrity.
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Affiliation(s)
- Aditya Kamat
- National Centre for Biological Sciences (TIFR), Bengaluru 560065, India
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5
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Hu QY, Pu XJ, Li GH, Li CQ, Lei HM, Zhang KQ, Zhao PJ. Identification and Mechanism of Action of the Global Secondary Metabolism Regulator SaraC in Stereum hirsutum. Microbiol Spectr 2022; 10:e0262422. [PMID: 36409127 PMCID: PMC9769804 DOI: 10.1128/spectrum.02624-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 11/04/2022] [Indexed: 11/23/2022] Open
Abstract
DNA methylation is an important factor in the regulation of gene expression. In analyzing genomic data of Stereum hirsutum FP-91666, we found a hypothetical bifunctional transcription regulator/O6Meguanine-DNA methyltransferase (named SaraC), which is widely present in both bacteria and fungi, and confirmed that its function in bacteria is mainly for DNA reparation. In this paper, we confirmed that SaraC has the function of DNA binding and demethylation through surface plasma resonance and reaction experiments in vitro. Then, we achieved the overexpression of SaraC (OES) in S. hirsutum, sequenced the methylation and transcription levels of the whole-genome, and further conducted untargeted metabolomics analyses of the OES transformants and the wild type (WT). The results confirmed that the overall-methylation levels of the transformants were significantly downregulated, and various genes related to secondary metabolism were upregulated. Through comparative untargeted metabolomic analyses, it showed that OES SA6 transformant produced a greater number of hybrid polyketides, and we identified 2 novel hybrid polyketides from the fermentation products of SA6. Our results show that overexpression SaraC can effectively stimulate the expression of secondary-metabolism-related genes, which could be a broad-spectrum tool for discovery of metabolites due to its cross-species conservation. IMPORTANCE Fungi are one of the important sources of active compounds. However, in fungi, most of the secondary metabolic biosynthetic gene clusters are weakly expressed or silenced under conventional culture conditions. How to efficiently excavate potential new compounds contained in fungi is becoming a research hot spot in the world. In this study, we found a DNA demethylation protein (SaraC) and confirmed that it is a global secondary metabolism regulator in Stereum hirsutum FP-91666. In the past, SaraC-like proteins were mainly regarded as DNA repair proteins, but our findings proved that it will be a powerful tool for mining secondary metabolites for overexpression of SaraC, which can effectively stimulate the expression of genes related to secondary metabolism.
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Affiliation(s)
- Qian-Yi Hu
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Xue-Juan Pu
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Guo-Hong Li
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Chun-Qiang Li
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Hong-Mei Lei
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Ke-Qin Zhang
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Pei-Ji Zhao
- State key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
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6
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Mazmanian K, Chen T, Sargsyan K, Lim C. From quantum-derived principles underlying cysteine reactivity to combating the COVID-19 pandemic. WILEY INTERDISCIPLINARY REVIEWS. COMPUTATIONAL MOLECULAR SCIENCE 2022; 12:e1607. [PMID: 35600063 PMCID: PMC9111396 DOI: 10.1002/wcms.1607] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/31/2022] [Accepted: 02/13/2022] [Indexed: 12/20/2022]
Abstract
The COVID‐19 pandemic poses a challenge in coming up with quick and effective means to counter its cause, the SARS‐CoV‐2. Here, we show how the key factors governing cysteine reactivity in proteins derived from combined quantum mechanical/continuum calculations led to a novel multi‐targeting strategy against SARS‐CoV‐2, in contrast to developing potent drugs/vaccines against a single viral target such as the spike protein. Specifically, they led to the discovery of reactive cysteines in evolutionary conserved Zn2+‐sites in several SARS‐CoV‐2 proteins that are crucial for viral polypeptide proteolysis as well as viral RNA synthesis, proofreading, and modification. These conserved, reactive cysteines, both free and Zn2+‐bound, can be targeted using the same Zn‐ejector drug (disulfiram/ebselen), which enables the use of broad‐spectrum anti‐virals that would otherwise be removed by the virus's proofreading mechanism. Our strategy of targeting multiple, conserved viral proteins that operate at different stages of the virus life cycle using a Zn‐ejector drug combined with other broad‐spectrum anti‐viral drug(s) could enhance the barrier to drug resistance and antiviral effects, as compared to each drug alone. Since these functionally important nonstructural proteins containing reactive cysteines are highly conserved among coronaviruses, our proposed strategy has the potential to tackle future coronaviruses. This article is categorized under:Structure and Mechanism > Reaction Mechanisms and Catalysis Structure and Mechanism > Computational Biochemistry and Biophysics Electronic Structure Theory > Density Functional Theory
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Affiliation(s)
| | - Ting Chen
- Institute of Biomedical Sciences Academia Sinica Taipei Taiwan
| | - Karen Sargsyan
- Institute of Biomedical Sciences Academia Sinica Taipei Taiwan
| | - Carmay Lim
- Institute of Biomedical Sciences Academia Sinica Taipei Taiwan.,Department of Chemistry National Tsing Hua University Hsinchu Taiwan
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7
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Vincent MS, Uphoff S. Cellular heterogeneity in DNA alkylation repair increases population genetic plasticity. Nucleic Acids Res 2021; 49:12320-12331. [PMID: 34850170 PMCID: PMC8643705 DOI: 10.1093/nar/gkab1143] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 10/27/2021] [Accepted: 11/03/2021] [Indexed: 11/29/2022] Open
Abstract
DNA repair mechanisms fulfil a dual role, as they are essential for cell survival and genome maintenance. Here, we studied how cells regulate the interplay between DNA repair and mutation. We focused on the adaptive response that increases the resistance of Escherichia coli cells to DNA alkylation damage. Combination of single-molecule imaging and microfluidic-based single-cell microscopy showed that noise in the gene activation timing of the master regulator Ada is accurately propagated to generate a distinct subpopulation of cells in which all proteins of the adaptive response are essentially absent. Whereas genetic deletion of these proteins causes extreme sensitivity to alkylation stress, a temporary lack of expression is tolerated and increases genetic plasticity of the whole population. We demonstrated this by monitoring the dynamics of nascent DNA mismatches during alkylation stress as well as the frequency of fixed mutations that are generated by the distinct subpopulations of the adaptive response. We propose that stochastic modulation of DNA repair capacity by the adaptive response creates a viable hypermutable subpopulation of cells that acts as a source of genetic diversity in a clonal population.
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Affiliation(s)
- Maxence S Vincent
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Stephan Uphoff
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
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8
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Stix R, Lee CJ, Faraldo-Gómez JD, Banerjee A. Structure and Mechanism of DHHC Protein Acyltransferases. J Mol Biol 2020; 432:4983-4998. [PMID: 32522557 DOI: 10.1016/j.jmb.2020.05.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 01/01/2023]
Abstract
S-acylation, whereby a fatty acid chain is covalently linked to a cysteine residue by a thioester linkage, is the most prevalent kind of lipid modification of proteins. Thousands of proteins are targets of this post-translational modification, which is catalyzed by a family of eukaryotic integral membrane enzymes known as DHHC protein acyltransferases (DHHC-PATs). Our knowledge of the repertoire of S-acylated proteins has been rapidly expanding owing to development of the chemoproteomic techniques. There has also been an increasing number of reports in the literature documenting the importance of S-acylation in human physiology and disease. Recently, the first atomic structures of two different DHHC-PATs were determined using X-ray crystallography. This review will focus on the insights gained into the molecular mechanism of DHHC-PATs from these structures and highlight representative data from the biochemical literature that they help explain.
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Affiliation(s)
- Robyn Stix
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chul-Jin Lee
- Unit on Structural and Chemical Biology of Membrane Proteins, Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - José D Faraldo-Gómez
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anirban Banerjee
- Unit on Structural and Chemical Biology of Membrane Proteins, Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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9
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Dai S, Holt MV, Horton JR, Woodcock CB, Patel A, Zhang X, Young NL, Wilkinson AW, Cheng X. Characterization of SETD3 methyltransferase-mediated protein methionine methylation. J Biol Chem 2020; 295:10901-10910. [PMID: 32503840 DOI: 10.1074/jbc.ra120.014072] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/03/2020] [Indexed: 12/20/2022] Open
Abstract
Most characterized protein methylation events encompass arginine and lysine N-methylation, and only a few cases of protein methionine thiomethylation have been reported. Newly discovered oncohistone mutations include lysine-to-methionine substitutions at positions 27 and 36 of histone H3.3. In these instances, the methionine substitution localizes to the active-site pocket of the corresponding histone lysine methyltransferase, thereby inhibiting the respective transmethylation activity. SET domain-containing 3 (SETD3) is a protein (i.e. actin) histidine methyltransferase. Here, we generated an actin variant in which the histidine target of SETD3 was substituted with methionine. As for previously characterized histone SET domain proteins, the methionine substitution substantially (76-fold) increased binding affinity for SETD3 and inhibited SETD3 activity on histidine. Unexpectedly, SETD3 was active on the substituted methionine, generating S-methylmethionine in the context of actin peptide. The ternary structure of SETD3 in complex with the methionine-containing actin peptide at 1.9 Å resolution revealed that the hydrophobic thioether side chain is packed by the aromatic rings of Tyr312 and Trp273, as well as the hydrocarbon side chain of Ile310 Our results suggest that placing methionine properly in the active site-within close proximity to and in line with the incoming methyl group of SAM-would allow some SET domain proteins to selectively methylate methionine in proteins.
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Affiliation(s)
- Shaobo Dai
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Matthew V Holt
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - John R Horton
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Clayton B Woodcock
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Anamika Patel
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Xing Zhang
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Nicolas L Young
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Alex W Wilkinson
- Department of Biology, Stanford University, Stanford, California, USA
| | - Xiaodong Cheng
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
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10
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Ma B, Villalta PW, Hochalter JB, Stepanov I, Hecht SS. Methyl DNA phosphate adduct formation in lung tumor tissue and adjacent normal tissue of lung cancer patients. Carcinogenesis 2020; 40:1387-1394. [PMID: 30873516 DOI: 10.1093/carcin/bgz053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/25/2019] [Accepted: 03/08/2019] [Indexed: 11/14/2022] Open
Abstract
The formation of methyl DNA adducts is a critical step in carcinogenesis initiated by the exposure to methylating carcinogens. Methyl DNA phosphate adducts, formed by methylation of the oxygen atoms of the DNA phosphate backbone, have been detected in animals treated with methylating carcinogens. However, detection of these adducts in human tissues has not been reported. We developed an ultrasensitive liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry method for detecting methyl DNA phosphate adducts. Using 50 μg of human lung DNA, a limit of quantitation of two adducts/1010 nucleobases was achieved. Twenty-two structurally unique methyl DNA phosphate adducts were detected in human lung DNA. The adduct levels were measured in both tumor and adjacent normal tissues from 30 patients with lung cancer, including 13 current smokers and 17 current non-smokers, as confirmed by measurements of urinary cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol. Levels of total methyl DNA phosphate adducts in normal lung tissues were higher in smokers than non-smokers, with an average of 13 and 8 adducts/109 nucleobases, respectively. Methyl DNA phosphate adducts were also detected in lung tissues from untreated rats with steady-state levels of 5-7 adducts/109 nucleobases over a period of 70 weeks. This is the first study to report the detection of methyl DNA phosphate adducts in human lung tissues. The results provide new insights toward using these DNA adducts as potential biomarkers to study human exposure to environmental methylating carcinogens.
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Affiliation(s)
- Bin Ma
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Peter W Villalta
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | | | - Irina Stepanov
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
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11
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Mazmanian K, Sargsyan K, Lim C. How the Local Environment of Functional Sites Regulates Protein Function. J Am Chem Soc 2020; 142:9861-9871. [PMID: 32407086 DOI: 10.1021/jacs.0c02430] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proteins form complex biological machineries whose functions in the cell are highly regulated at both the cellular and molecular levels. Cellular regulation of protein functions involves differential gene expressions, post-translation modifications, and signaling cascades. Molecular regulation, on the other hand, involves tuning an optimal local protein environment for the functional site. Precisely how a protein achieves such an optimal environment around a given functional site is not well understood. Herein, by surveying the literature, we first summarize the various reported strategies used by certain proteins to ensure their correct functioning. We then formulate three key physicochemical factors for regulating a protein's functional site, namely, (i) its immediate interactions, (ii) its solvent accessibility, and (iii) its conformational flexibility. We illustrate how these factors are applied to regulate the functions of free/metal-bound Cys and Zn sites in proteins.
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Affiliation(s)
- Karine Mazmanian
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Karen Sargsyan
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Carmay Lim
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.,Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
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12
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Wu J, Yuan J, Price NE, Wang Y. Ada protein- and sequence context-dependent mutagenesis of alkyl phosphotriester lesions in Escherichia coli cells. J Biol Chem 2020; 295:8775-8783. [PMID: 32381504 DOI: 10.1074/jbc.ra120.013657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/01/2020] [Indexed: 11/06/2022] Open
Abstract
Alkyl phosphotriester (alkyl-PTE) lesions are frequently induced in DNA and are resistant to repair. Here, we synthesized and characterized methyl (Me)- and n-butyl (nBu)-PTEs in two diastereomeric configurations (S p and R p) at six different flanking dinucleotide sites, i.e. XT and TX (X = A, C, or G), and assessed how these lesions impact DNA replication in Escherichia coli cells. When single-stranded vectors contained an S p-Me-PTE in the sequence contexts of 5'-AT-3', 5'-CT-3', or 5'-GT-3', DNA replication was highly efficient and the replication products for all three sequence contexts contained 85-90% AT and 5-10% TG. Thus, the replication outcome was largely independent of the identity of the 5' nucleotide adjacent to an S p-Me-PTE. Furthermore, replication across these lesions was not dependent on the activities of DNA polymerases II, IV, or V; Ada, a protein involved in adaptive response and repair of S p-Me-PTE in E. coli, however, was essential for the generation of the mutagenic products. Additionally, the R p diastereomer of Me-PTEs at XT sites and both diastereomers of Me-PTEs at TX sites exhibited error-free replication bypass. Moreover, S p-nBu-PTEs at XT sites did not strongly impede DNA replication, and other nBu-PTEs displayed moderate blockage effects, with none of them being mutagenic. Taken together, these findings provide in-depth understanding of how alkyl-PTE lesions are recognized by the DNA replication machinery in prokaryotic cells and reveal that Ada contributes to mutagenesis of S p-Me-PTEs in E. coli.
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Affiliation(s)
- Jiabin Wu
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA
| | - Jun Yuan
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA
| | - Nathan E Price
- Department of Chemistry, University of California, Riverside, California, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA; Department of Chemistry, University of California, Riverside, California, USA.
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13
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Wu J, Wang P, Wang Y. Cytotoxic and mutagenic properties of alkyl phosphotriester lesions in Escherichia coli cells. Nucleic Acids Res 2019. [PMID: 29514270 PMCID: PMC5934668 DOI: 10.1093/nar/gky140] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Exposure to many endogenous and exogenous agents can give rise to DNA alkylation, which constitutes a major type of DNA damage. Among the DNA alkylation products, alkyl phosphotriesters have relatively high frequencies of occurrence and are resistant to repair in mammalian tissues. However, little is known about how these lesions affect the efficiency and fidelity of DNA replication in cells or how the replicative bypass of these lesions is modulated by translesion synthesis DNA polymerases. In this study, we synthesized oligodeoxyribonucleotides containing four pairs (Sp and Rp) of alkyl phosphotriester lesions at a defined site, and examined how these lesions are recognized by DNA replication machinery in Escherichia coli cells. We found that the Sp diastereomer of the alkyl phosphotriester lesions could be efficiently bypassed, whereas the Rp counterparts moderately blocked DNA replication. Moreover, the Sp-methyl phosphotriester induced TT→GT and TT→GC mutations at the flanking TT dinucleotide site, and the induction of these mutations required Ada protein, which is known to remove efficiently the methyl group from the Sp-methyl phosphotriester. Together, our study provided a comprehensive understanding about the recognition of alkyl phosphotriester lesions by DNA replication machinery in cells, and revealed for the first time the Ada-dependent induction of mutations at the Sp-methyl phosphotriester site.
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Affiliation(s)
- Jiabin Wu
- Environmental Toxicology Graduate Program and Department of Chemistry, University of California Riverside, Riverside, CA 92521-0403, USA
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program and Department of Chemistry, University of California Riverside, Riverside, CA 92521-0403, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program and Department of Chemistry, University of California Riverside, Riverside, CA 92521-0403, USA
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14
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Peer E, Moshitch-Moshkovitz S, Rechavi G, Dominissini D. The Epitranscriptome in Translation Regulation. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032623. [PMID: 30037968 DOI: 10.1101/cshperspect.a032623] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The cellular proteome reflects the total outcome of many regulatory mechanisms that affect the metabolism of messenger RNA (mRNA) along its pathway from synthesis to degradation. Accumulating evidence in recent years has uncovered the roles of a growing number of mRNA modifications in every step along this pathway, shaping translational output. mRNA modifications affect the translation machinery directly, by influencing translation initiation, elongation and termination, or by altering mRNA levels and subcellular localization. Features of modification-related translational control are described, charting a new and complex layer of translational regulation.
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Affiliation(s)
- Eyal Peer
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Cancer Research Center and Wohl Centre for Translational Medicine, Chaim Sheba Medical Center, Tel-Hashomer 5262160, Israel
| | - Sharon Moshitch-Moshkovitz
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Cancer Research Center and Wohl Centre for Translational Medicine, Chaim Sheba Medical Center, Tel-Hashomer 5262160, Israel
| | - Gideon Rechavi
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Cancer Research Center and Wohl Centre for Translational Medicine, Chaim Sheba Medical Center, Tel-Hashomer 5262160, Israel
| | - Dan Dominissini
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Cancer Research Center and Wohl Centre for Translational Medicine, Chaim Sheba Medical Center, Tel-Hashomer 5262160, Israel
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15
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Ma B, Stepanov I, Hecht SS. Recent Studies on DNA Adducts Resulting from Human Exposure to Tobacco Smoke. TOXICS 2019; 7:E16. [PMID: 30893918 PMCID: PMC6468371 DOI: 10.3390/toxics7010016] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/09/2019] [Accepted: 03/13/2019] [Indexed: 12/22/2022]
Abstract
DNA adducts are believed to play a central role in the induction of cancer in cigarette smokers and are proposed as being potential biomarkers of cancer risk. We have summarized research conducted since 2012 on DNA adduct formation in smokers. A variety of DNA adducts derived from various classes of carcinogens, including aromatic amines, polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, alkylating agents, aldehydes, volatile carcinogens, as well as oxidative damage have been reported. The results are discussed with particular attention to the analytical methods used in those studies. Mass spectrometry-based methods that have higher selectivity and specificity compared to 32P-postlabeling or immunochemical approaches are preferred. Multiple DNA adducts specific to tobacco constituents have also been characterized for the first time in vitro or detected in vivo since 2012, and descriptions of those adducts are included. We also discuss common issues related to measuring DNA adducts in humans, including the development and validation of analytical methods and prevention of artifact formation.
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Affiliation(s)
- Bin Ma
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Irina Stepanov
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
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16
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Kluska K, Adamczyk J, Krężel A. Metal binding properties, stability and reactivity of zinc fingers. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.04.009] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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17
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de Paiva REF, Du Z, Nakahata DH, Lima FA, Corbi PP, Farrell NP. Gold‐Catalyzed C–S Aryl‐Group Transfer in Zinc Finger Proteins. Angew Chem Int Ed Engl 2018; 57:9305-9309. [DOI: 10.1002/anie.201803082] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/02/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Raphael E. F. de Paiva
- Department of Chemistry Virginia Commonwealth University 1001 W. Main Street Richmond VA 23284-2006 USA
- Institute of Chemistry University of Campinas—UNICAMP P.O. Box 6154, CEP 13083-970 Campinas, São Paulo Brazil
| | - Zhifeng Du
- Department of Chemistry Virginia Commonwealth University 1001 W. Main Street Richmond VA 23284-2006 USA
| | - Douglas H. Nakahata
- Institute of Chemistry University of Campinas—UNICAMP P.O. Box 6154, CEP 13083-970 Campinas, São Paulo Brazil
| | - Frederico A. Lima
- Centro Nacional de Pesquisa em Energia e Materiais Brazilian Synchrotron Light Laboratory—LNLS, 13084-971 Campinas SP Brazil
- European XFEL GmbH Holzkoppel 4 22869 Schenefeld Germany
| | - Pedro P. Corbi
- Institute of Chemistry University of Campinas—UNICAMP P.O. Box 6154, CEP 13083-970 Campinas, São Paulo Brazil
| | - Nicholas P. Farrell
- Department of Chemistry Virginia Commonwealth University 1001 W. Main Street Richmond VA 23284-2006 USA
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18
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de Paiva REF, Du Z, Nakahata DH, Lima FA, Corbi PP, Farrell NP. Gold‐Catalyzed C–S Aryl‐Group Transfer in Zinc Finger Proteins. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201803082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Raphael E. F. de Paiva
- Department of Chemistry Virginia Commonwealth University 1001 W. Main Street Richmond VA 23284-2006 USA
- Institute of Chemistry University of Campinas—UNICAMP P.O. Box 6154, CEP 13083-970 Campinas, São Paulo Brazil
| | - Zhifeng Du
- Department of Chemistry Virginia Commonwealth University 1001 W. Main Street Richmond VA 23284-2006 USA
| | - Douglas H. Nakahata
- Institute of Chemistry University of Campinas—UNICAMP P.O. Box 6154, CEP 13083-970 Campinas, São Paulo Brazil
| | - Frederico A. Lima
- Centro Nacional de Pesquisa em Energia e Materiais Brazilian Synchrotron Light Laboratory—LNLS, 13084-971 Campinas SP Brazil
- European XFEL GmbH Holzkoppel 4 22869 Schenefeld Germany
| | - Pedro P. Corbi
- Institute of Chemistry University of Campinas—UNICAMP P.O. Box 6154, CEP 13083-970 Campinas, São Paulo Brazil
| | - Nicholas P. Farrell
- Department of Chemistry Virginia Commonwealth University 1001 W. Main Street Richmond VA 23284-2006 USA
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19
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Ma B, Zarth AT, Carlson ES, Villalta PW, Upadhyaya P, Stepanov I, Hecht SS. Methyl DNA Phosphate Adduct Formation in Rats Treated Chronically with 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone and Enantiomers of Its Metabolite 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol. Chem Res Toxicol 2018; 31:48-57. [PMID: 29131934 PMCID: PMC5770887 DOI: 10.1021/acs.chemrestox.7b00281] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Indexed: 11/29/2022]
Abstract
The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a powerful lung carcinogen in animal models and is considered a causative factor for lung cancer in tobacco users. NNK is stereoselectively and reversibly metabolized to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which is also a lung carcinogen. Both NNK and NNAL undergo metabolic activation by α-hydroxylation on their methyl groups to form pyridyloxobutyl and pyridylhydroxybutyl DNA base and phosphate adducts, respectively. α-Hydroxylation also occurs on the α-methylene carbons of NNK and NNAL to produce methane diazohydroxide, which reacts with DNA to form methyl DNA base adducts. DNA adducts of NNK and NNAL are important in their mechanisms of carcinogenesis. In this study, we characterized and quantified methyl DNA phosphate adducts in the lung of rats treated with 5 ppm of NNK, (S)-NNAL, or (R)-NNAL in drinking water for 10, 30, 50, and 70 weeks, by using a novel liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry method. A total of 23, 21, and 22 out of 32 possible methyl DNA phosphate adducts were detected in the lung tissues of rats treated with NNK, (S)-NNAL, and (R)-NNAL, respectively. Levels of the methyl DNA phosphate adducts were 2290-4510, 872-1120, and 763-1430 fmol/mg DNA, accounting for 15-38%, 8%, and 5-9% of the total measured DNA adducts in rats treated with NNK, (S)-NNAL, and (R)-NNAL, respectively. The methyl DNA phosphate adducts characterized in this study further enriched the diversity of DNA adducts formed by NNK and NNAL. These results provide important new data regarding NNK- and NNAL-derived DNA damage and new insights pertinent to future mechanistic and biomonitoring studies of NNK, NNAL, and other chemical methylating agents.
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Affiliation(s)
- Bin Ma
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
| | - Adam T. Zarth
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
| | - Erik S. Carlson
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
| | - Peter W. Villalta
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
| | - Pramod Upadhyaya
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
| | - Irina Stepanov
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, 2231 Sixth Street SE, 2-152 CCRB, Minneapolis, Minnesota 55455, United States
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20
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Classification of the treble clef zinc finger: noteworthy lessons for structure and function evolution. Sci Rep 2016; 6:32070. [PMID: 27562564 PMCID: PMC4999995 DOI: 10.1038/srep32070] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/02/2016] [Indexed: 11/08/2022] Open
Abstract
Treble clef (TC) zinc fingers constitute a large fold-group of structural zinc-binding protein domains that mediate numerous cellular functions. We have analysed the sequence, structure, and function relationships among all TCs in the Protein Data Bank. This led to the identification of novel TCs, such as lsr2, YggX and TFIIIC τ 60 kDa subunit, and prediction of a nuclease-like function for the DUF1364 family. The structural malleability of TCs is evident from the many examples with variations to the core structural elements of the fold. We observe domains wherein the structural core of the TC fold is circularly permuted, and also some examples where the overall fold resembles both the TC motif and another unrelated fold. All extant TC families do not share a monophyletic origin, as several TC proteins are known to have been present in the last universal common ancestor and the last eukaryotic common ancestor. We identify several TCs where the zinc-chelating site and residues are not merely responsible for structure stabilization but also perform other functions, such as being redox active in C1B domain of protein kinase C, a nucleophilic acceptor in Ada and catalytic in organomercurial lyase, MerB.
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21
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Abstract
The presence of an N 1 methyl group on adenine bases in DNA and RNA was thought to be a form of damage. Results now show that it also occurs at specific sites in messenger RNAs, where it affects protein expression.
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Affiliation(s)
- Anna M Kietrys
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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22
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Dominissini D, Nachtergaele S, Moshitch-Moshkovitz S, Peer E, Kol N, Ben-Haim MS, Dai Q, Di Segni A, Salmon-Divon M, Clark WC, Zheng G, Pan T, Solomon O, Eyal E, Hershkovitz V, Han D, Doré LC, Amariglio N, Rechavi G, He C. The dynamic N(1)-methyladenosine methylome in eukaryotic messenger RNA. Nature 2016; 530:441-6. [PMID: 26863196 DOI: 10.1038/nature16998] [Citation(s) in RCA: 670] [Impact Index Per Article: 83.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/15/2016] [Indexed: 12/26/2022]
Abstract
Gene expression can be regulated post-transcriptionally through dynamic and reversible RNA modifications. A recent noteworthy example is N(6)-methyladenosine (m(6)A), which affects messenger RNA (mRNA) localization, stability, translation and splicing. Here we report on a new mRNA modification, N(1)-methyladenosine (m(1)A), that occurs on thousands of different gene transcripts in eukaryotic cells, from yeast to mammals, at an estimated average transcript stoichiometry of 20% in humans. Employing newly developed sequencing approaches, we show that m(1)A is enriched around the start codon upstream of the first splice site: it preferentially decorates more structured regions around canonical and alternative translation initiation sites, is dynamic in response to physiological conditions, and correlates positively with protein production. These unique features are highly conserved in mouse and human cells, strongly indicating a functional role for m(1)A in promoting translation of methylated mRNA.
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Affiliation(s)
- Dan Dominissini
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Sigrid Nachtergaele
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | | | - Eyal Peer
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitzan Kol
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Moshe Shay Ben-Haim
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Qing Dai
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Ayelet Di Segni
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Mali Salmon-Divon
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Wesley C Clark
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Guanqun Zheng
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Tao Pan
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Oz Solomon
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.,The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Eran Eyal
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Vera Hershkovitz
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Dali Han
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Louis C Doré
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Ninette Amariglio
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.,The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Gideon Rechavi
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Chuan He
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
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23
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Buck HM. The Risk of the Preparation of Artificial DNAs via an Interrupted Automated Solid-Phase Triester Method. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2016; 34:400-15. [PMID: 25965329 DOI: 10.1080/15257770.2015.1006774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In this paper, the risk of the preparation of artificial DNAs via an interrupted automated solid-phase triester procedure is discussed. These results differ completely from the corresponding results obtained by a gradual non-automated synthesis, indicated as solution-phase chemistry. With experimental results focused on model systems under various conditions and molecular-mechanics calculations, it feels as a challenge to offer an explanation for this different behavior. Attention is briefly given to click-linked DNA fragments as a substitute of phosphate linkages.
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Affiliation(s)
- Henk M Buck
- a Professor Emeritus , Tilburg , The Netherlands
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24
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Yang C, Chang CH. Exploring comprehensive within-motif dependence of transcription factor binding in Escherichia coli. Sci Rep 2015; 5:17021. [PMID: 26592556 PMCID: PMC4655474 DOI: 10.1038/srep17021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/16/2015] [Indexed: 01/18/2023] Open
Abstract
Modeling the binding of transcription factors helps to decipher the control logic behind transcriptional regulatory networks. Position weight matrix is commonly used to describe a binding motif but assumes statistical independence between positions. Although current approaches take within-motif dependence into account for better predictive performance, these models usually rely on prior knowledge and incorporate simple positional dependence to describe binding motifs. The inability to take complex within-motif dependence into account may result in an incomplete representation of binding motifs. In this work, we applied association rule mining techniques and constructed models to explore within-motif dependence for transcription factors in Escherichia coli. Our models can reflect transcription factor-DNA recognition where the explored dependence correlates with the binding specificity. We also propose a graphical representation of the explored within-motif dependence to illustrate the final binding configurations. Understanding the binding configurations also enables us to fine-tune or design transcription factor binding sites, and we attempt to present the configurations through exploring within-motif dependence.
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Affiliation(s)
- Chi Yang
- Institute of Biomedical Informatics, National Yang Ming University, Taipei, 11221, Taiwan
| | - Chuan-Hsiung Chang
- Institute of Biomedical Informatics, National Yang Ming University, Taipei, 11221, Taiwan.,Center for Systems and Synthetic Biology, National Yang Ming University, Taipei, 11221, Taiwan
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25
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Mielecki D, Wrzesiński M, Grzesiuk E. Inducible repair of alkylated DNA in microorganisms. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 763:294-305. [PMID: 25795127 DOI: 10.1016/j.mrrev.2014.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/01/2014] [Accepted: 12/02/2014] [Indexed: 12/15/2022]
Abstract
Alkylating agents, which are widespread in the environment, also occur endogenously as primary and secondary metabolites. Such compounds have intrinsically extremely cytotoxic and frequently mutagenic effects, to which organisms have developed resistance by evolving multiple repair mechanisms to protect cellular DNA. One such defense against alkylation lesions is an inducible Adaptive (Ada) response. In Escherichia coli, the Ada response enhances cell resistance by the biosynthesis of four proteins: Ada, AlkA, AlkB, and AidB. The glycosidic bonds of the most cytotoxic lesion, N3-methyladenine (3meA), together with N3-methylguanine (3meG), O(2)-methylthymine (O(2)-meT), and O(2)-methylcytosine (O(2)-meC), are cleaved by AlkA DNA glycosylase. Lesions such as N1-methyladenine (1meA) and N3-methylcytosine (3meC) are removed from DNA and RNA by AlkB dioxygenase. Cytotoxic and mutagenic O(6)-methylguanine (O(6)meG) is repaired by Ada DNA methyltransferase, which transfers the methyl group onto its own cysteine residue from the methylated oxygen. We review (i) the individual Ada proteins Ada, AlkA, AlkB, AidB, and COG3826, with emphasis on the ubiquitous and versatile AlkB and its prokaryotic and eukaryotic homologs; (ii) the organization of the Ada regulon in several bacterial species; (iii) the mechanisms underlying activation of Ada transcription. In vivo and in silico analysis of various microorganisms shows the widespread existence and versatile organization of Ada regulon genes, including not only ada, alkA, alkB, and aidB but also COG3826, alkD, and other genes whose roles in repair of alkylated DNA remain to be elucidated. This review explores the comparative organization of Ada response and protein functions among bacterial species beyond the classical E. coli model.
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Affiliation(s)
- Damian Mielecki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Michał Wrzesiński
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Elżbieta Grzesiuk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland.
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26
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Mielecki D, Grzesiuk E. Ada response - a strategy for repair of alkylated DNA in bacteria. FEMS Microbiol Lett 2014; 355:1-11. [PMID: 24810496 PMCID: PMC4437013 DOI: 10.1111/1574-6968.12462] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/04/2014] [Accepted: 05/05/2014] [Indexed: 11/29/2022] Open
Abstract
Alkylating agents are widespread in the environment and also occur endogenously. They can be cytotoxic or mutagenic to the cells introducing alkylated bases to DNA or RNA. All organisms have evolved multiple DNA repair mechanisms to counteract the effects of DNA alkylation: the most cytotoxic lesion, N3-methyladenine (3meA), is excised by AlkA glycosylase initiating base excision repair (BER); toxic N1-methyladenine (1meA) and N3-methylcytosine (3meC), induced in DNA and RNA, are removed by AlkB dioxygenase; and mutagenic and cytotoxic O6-methylguanine (O6meG) is repaired by Ada methyltransferase. In Escherichia coli, Ada response involves the expression of four genes, ada, alkA, alkB, and aidB, encoding respective proteins Ada, AlkA, AlkB, and AidB. The Ada response is conserved among many bacterial species; however, it can be organized differently, with diverse substrate specificity of the particular proteins. Here, an overview of the organization of the Ada regulon and function of individual proteins is presented. We put special effort into the characterization of AlkB dioxygenases, their substrate specificity, and function in the repair of alkylation lesions in DNA/RNA.
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Affiliation(s)
- Damian Mielecki
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, Poland
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27
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Shannon DA, Weerapana E. Orphan PTMs: Rare, yet functionally important modifications of cysteine. Biopolymers 2013; 101:156-64. [DOI: 10.1002/bip.22252] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 04/01/2013] [Indexed: 12/16/2022]
Affiliation(s)
- D. Alexander Shannon
- Department of Chemistry; Merkert Chemistry Center, Boston College; Chestnut Hill MA 02467
| | - Eranthie Weerapana
- Department of Chemistry; Merkert Chemistry Center, Boston College; Chestnut Hill MA 02467
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28
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Booth JA, Thomassen GOS, Rowe AD, Weel-Sneve R, Lagesen K, Kristiansen KI, Bjørås M, Rognes T, Lindvall JM. Tiling array study of MNNG treated Escherichia coli reveals a widespread transcriptional response. Sci Rep 2013; 3:3053. [PMID: 24157950 PMCID: PMC6505713 DOI: 10.1038/srep03053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/11/2013] [Indexed: 11/25/2022] Open
Abstract
The alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is known to trigger the adaptive response by inducing the ada-regulon – consisting of three DNA repair enzymes Ada, AlkB, AlkA and the enigmatic AidB. We have applied custom designed tiling arrays to study transcriptional changes in Escherichia coli following a MNNG challenge. Along with the expected upregulation of the adaptive response genes (ada, alkA and alkB), we identified a number of differentially expressed transcripts, both novel and annotated. This indicates a wider regulatory response than previously documented. There were 250 differentially-expressed and 2275 similarly-expressed unannotated transcripts. We found novel upregulation of several stress-induced transcripts, including the SOS inducible genes recN and tisAB, indicating a novel role for these genes in alkylation repair. Furthermore, the ada-regulon A and B boxes were found to be insufficient to explain the regulation of the adaptive response genes after MNNG exposure, suggesting that additional regulatory elements must be involved.
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Affiliation(s)
- James A Booth
- 1] Centre for Molecular Biology and Neuroscience (CMBN) and Department of Microbiology, Oslo University Hospital, Rikshospitalet, PO Box 4950 Nydalen, NO-0424 Oslo, Norway [2] Department of Microbiology, University of Oslo, PO Box 4950 Nydalen, NO-0424 Oslo, Norway [3]
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29
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Moser F, Horwitz A, Chen J, Lim WA, Voigt CA. Genetic sensor for strong methylating compounds. ACS Synth Biol 2013; 2:614-24. [PMID: 24032656 DOI: 10.1021/sb400086p] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Methylating chemicals are common in industry and agriculture and are often toxic, partly due to their propensity to methylate DNA. The Escherichia coli Ada protein detects methylating compounds by sensing aberrant methyl adducts on the phosphoester backbone of DNA. We characterize this system as a genetic sensor and engineer it to lower the detection threshold. By overexpressing Ada from a plasmid, we improve the sensor’s dynamic range to 350-fold induction and lower its detection threshold to 40 μM for methyl iodide. In eukaryotes, there is no known sensor of methyl adducts on the phosphoester backbone of DNA. By fusing the N-terminal domain of Ada to the Gal4 transcriptional activation domain, we built a functional sensor for methyl phosphotriester adducts in Saccharomyces cerevisiae. This sensor can be tuned to variable specifications by altering the expression level of the chimeric sensor and changing the number of Ada operators upstream of the Gal4-sensitive reporter promoter. These changes result in a detection threshold of 28 μM and 5.2-fold induction in response to methyl iodide. When the yeast sensor is exposed to different SN1 and SN2 alkylating compounds, its response profile is similar to that observed for the native Ada protein in E. coli, indicating that its native function is retained in yeast. Finally, we demonstrate that the specifications achieved for the yeast sensor are suitable for detecting methylating compounds at relevant concentrations in environmental samples. This work demonstrates the movement of a sensor from a prokaryotic to eukaryotic system and its rational tuning to achieve desired specifications.
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Affiliation(s)
- Felix Moser
- Synthetic Biology
Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Andrew Horwitz
- Howard
Hughes
Medical Institute and Department of Cellular and Molecular Pharmacology, University of California—San Francisco, San Francisco, California 94158, United States
| | - Jacinto Chen
- Howard
Hughes
Medical Institute and Department of Cellular and Molecular Pharmacology, University of California—San Francisco, San Francisco, California 94158, United States
| | - Wendell A. Lim
- Howard
Hughes
Medical Institute and Department of Cellular and Molecular Pharmacology, University of California—San Francisco, San Francisco, California 94158, United States
| | - Christopher A. Voigt
- Synthetic Biology
Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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Mielecki D, Saumaa S, Wrzesiński M, Maciejewska AM, Żuchniewicz K, Sikora A, Piwowarski J, Nieminuszczy J, Kivisaar M, Grzesiuk E. Pseudomonas putida AlkA and AlkB proteins comprise different defense systems for the repair of alkylation damage to DNA - in vivo, in vitro, and in silico studies. PLoS One 2013; 8:e76198. [PMID: 24098441 PMCID: PMC3788762 DOI: 10.1371/journal.pone.0076198] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 08/19/2013] [Indexed: 11/18/2022] Open
Abstract
Alkylating agents introduce cytotoxic and/or mutagenic lesions to DNA bases leading to induction of adaptive (Ada) response, a mechanism protecting cells against deleterious effects of environmental chemicals. In Escherichia coli, the Ada response involves expression of four genes: ada, alkA, alkB, and aidB. In Pseudomonas putida, the organization of Ada regulon is different, raising questions regarding regulation of Ada gene expression. The aim of the presented studies was to analyze the role of AlkA glycosylase and AlkB dioxygenase in protecting P. putida cells against damage to DNA caused by alkylating agents. The results of bioinformatic analysis, of survival and mutagenesis of methyl methanesulfonate (MMS) or N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) treated P. putida mutants in ada, alkA and alkB genes as well as assay of promoter activity revealed diverse roles of Ada, AlkA and AlkB proteins in protecting cellular DNA against alkylating agents. We found AlkA protein crucial to abolish the cytotoxic but not the mutagenic effects of alkylans since: (i) the mutation in the alkA gene was the most deleterious for MMS/MNNG treated P. putida cells, (ii) the activity of the alkA promoter was Ada-dependent and the highest among the tested genes. P. putida AlkB (PpAlkB), characterized by optimal conditions for in vitro repair of specific substrates, complementation assay, and M13/MS2 survival test, allowed to establish conservation of enzymatic function of P. putida and E. coli AlkB protein. We found that the organization of P. putida Ada regulon differs from that of E. coli. AlkA protein induced within the Ada response is crucial for protecting P. putida against cytotoxicity, whereas Ada prevents the mutagenic action of alkylating agents. In contrast to E. coli AlkB (EcAlkB), PpAlkB remains beyond the Ada regulon and is expressed constitutively. It probably creates a backup system that protects P. putida strains defective in other DNA repair systems against alkylating agents of exo- and endogenous origin.
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Affiliation(s)
- Damian Mielecki
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Signe Saumaa
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Michał Wrzesiński
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka M. Maciejewska
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Karolina Żuchniewicz
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Sikora
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Jan Piwowarski
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Jadwiga Nieminuszczy
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Maia Kivisaar
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
- * E-mail: (EG); (MK)
| | - Elżbieta Grzesiuk
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- * E-mail: (EG); (MK)
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Jacques A, Mettra B, Lebrun V, Latour JM, Sénèque O. On the design of zinc-finger models with cyclic peptides bearing a linear tail. Chemistry 2013; 19:3921-31. [PMID: 23436718 DOI: 10.1002/chem.201204167] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Indexed: 11/07/2022]
Abstract
Cyclic peptides with a linear tail (CPLT) have been successfully used to model two zinc fingers (ZFs) adopting the treble-clef- and loosened zinc-ribbon folds. In this article, we examine the factors that may influence the design of such ZF models: mutations in the sequence, size of the cycle, and size of the tail. For this purpose, several peptides derived from the CPLT-based models of the treble-clef- and loosened zinc-ribbon ZF were synthesized and studied. CPLT-based models appear to be robust toward mutations, accommodate various cycle sizes, and are sensible to the size of the linking region of the tail located between the cycle and the coordinating amino acids. Based on these criteria, we describe the design of a new CPLT-based model for the zinc-ribbon ZFs, LZR , and compare it to a linear analogue, LZR(lin) . The model complex Zn⋅LZR is able to fold correctly around the metal ion contrary to Zn⋅LZR(lin) , suggesting that CPLT-based models are more likely to yield structurally meaningful models of ZF sites than linear peptide models. Finally, we draw some rules that could allow the design of new CPLT-based metallopeptides with a controlled fold.
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Affiliation(s)
- Aurélie Jacques
- Laboratoire de Chimie et Biologie des Métaux, Equipe de Physicochimie des Métaux en Biologie, UMR 5249 CNRS/CEA-DSV-iRTSV/, Université Joseph Fourier, 17 rue des Martyrs, Grenoble 38054, France
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Abstract
Endogenous and exogenous factors constantly challenge cellular DNA, generating cytotoxic and/or mutagenic DNA adducts. As a result, organisms have evolved different mechanisms to defend against the deleterious effects of DNA damage. Among these diverse repair pathways, direct DNA-repair systems provide cells with simple yet efficient solutions to reverse covalent DNA adducts. In this review, we focus on recent advances in the field of direct DNA repair, namely, photolyase-, alkyltransferase-, and dioxygenase-mediated repair processes. We present specific examples to describe new findings of known enzymes and appealing discoveries of new proteins. At the end of this article, we also briefly discuss the influence of direct DNA repair on other fields of biology and its implication on the discovery of new biology.
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Affiliation(s)
- Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
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Galardon E, Roger T, Deschamps P, Roussel P, Tomas A, Artaud I. Synthesis of a FeIISH Complex Stabilized by an Intramolecular N–H···S Hydrogen Bond, Which Acts as a H2S Donor. Inorg Chem 2012; 51:10068-70. [DOI: 10.1021/ic300952d] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Erwan Galardon
- Laboratoire de Chimie et Biochimie
Pharmacologique et Toxicologique, UMR 8601 CNRS, Université Paris Descartes, PRES
Paris cité, 45 rue des Saints Pères, 75270 Paris Cedex
06, France
| | - Thomas Roger
- Laboratoire de Chimie et Biochimie
Pharmacologique et Toxicologique, UMR 8601 CNRS, Université Paris Descartes, PRES
Paris cité, 45 rue des Saints Pères, 75270 Paris Cedex
06, France
| | - Patrick Deschamps
- Laboratoire
de Crystallographie
et RMN Biologiques, UMR 8015 CNRS, Université Paris Descartes, PRES Paris cité, 4 avenue de
l’Observatoire, 75270 Paris Cedex 06, France
| | - Pascal Roussel
- Unité de Catalyse et Chimie
du Solide (UCCS), UMR 8012 CNRS, École Nationale Supérieure de Chimie de Lille, BP 90108, 59652
Villeneuve d’Ascq Cedex, France
| | - Alain Tomas
- Laboratoire
de Crystallographie
et RMN Biologiques, UMR 8015 CNRS, Université Paris Descartes, PRES Paris cité, 4 avenue de
l’Observatoire, 75270 Paris Cedex 06, France
| | - Isabelle Artaud
- Laboratoire de Chimie et Biochimie
Pharmacologique et Toxicologique, UMR 8601 CNRS, Université Paris Descartes, PRES
Paris cité, 45 rue des Saints Pères, 75270 Paris Cedex
06, France
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Stewart MD, Igumenova TI. Reactive cysteine in the structural Zn(2+) site of the C1B domain from PKCα. Biochemistry 2012; 51:7263-77. [PMID: 22913772 DOI: 10.1021/bi300750w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Structural cysteine-rich Zn(2+) sites that stabilize protein folds are considered to be unreactive. In this article, we identified a reactive cysteine residue, Cys151, in a treble-clef zinc finger with a Cys(3)His coordination sphere. The protein in question is the C1B domain of Protein Kinase Cα (PKCα). Mass-tagging cysteine assays of several C1B variants were employed to ascertain the site specificity of the covalent modification. The reactivity of Cys151 in C1B also manifests itself in the structural dynamics of the Zn(2+) coordination sphere where the Sγ of Cys151 alternates between the Zn(2+)-bound thiolate and free thiol states. We used NMR-detected pH titrations, ZZ-exchange spectroscopy, and residual dipolar coupling (RDC)-driven structure refinement to characterize the two exchanging conformations of C1B that differ in zinc coordination. Our data suggest that Cys151 serves as an entry point for the reactive oxygen species that activate PKCα in a process involving Zn(2+) release.
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Affiliation(s)
- Mikaela D Stewart
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States
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Malhotra S, Sowdhamini R. Re-visiting protein-centric two-tier classification of existing DNA-protein complexes. BMC Bioinformatics 2012; 13:165. [PMID: 22800292 PMCID: PMC3472317 DOI: 10.1186/1471-2105-13-165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 03/26/2012] [Indexed: 01/28/2023] Open
Abstract
Background Precise DNA-protein interactions play most important and vital role in maintaining the normal physiological functioning of the cell, as it controls many high fidelity cellular processes. Detailed study of the nature of these interactions has paved the way for understanding the mechanisms behind the biological processes in which they are involved. Earlier in 2000, a systematic classification of DNA-protein complexes based on the structural analysis of the proteins was proposed at two tiers, namely groups and families. With the advancement in the number and resolution of structures of DNA-protein complexes deposited in the Protein Data Bank, it is important to revisit the existing classification. Results On the basis of the sequence analysis of DNA binding proteins, we have built upon the protein centric, two-tier classification of DNA-protein complexes by adding new members to existing families and making new families and groups. While classifying the new complexes, we also realised the emergence of new groups and families. The new group observed was where β-propeller was seen to interact with DNA. There were 34 SCOP folds which were observed to be present in the complexes of both old and new classifications, whereas 28 folds are present exclusively in the new complexes. Some new families noticed were NarL transcription factor, Z-α DNA binding proteins, Forkhead transcription factor, AP2 protein, Methyl CpG binding protein etc. Conclusions Our results suggest that with the increasing number of availability of DNA-protein complexes in Protein Data Bank, the number of families in the classification increased by approximately three fold. The folds present exclusively in newly classified complexes is suggestive of inclusion of proteins with new function in new classification, the most populated of which are the folds responsible for DNA damage repair. The proposed re-visited classification can be used to perform genome-wide surveys in the genomes of interest for the presence of DNA-binding proteins. Further analysis of these complexes can aid in developing algorithms for identifying DNA-binding proteins and their family members from mere sequence information.
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Affiliation(s)
- Sony Malhotra
- National Centre for Biological Sciences, UAS-GKVK Campus, Bangalore 560 065, India
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Young BD, Weiss DI, Zurita-Lopez CI, Webb KJ, Clarke SG, McBride AE. Identification of methylated proteins in the yeast small ribosomal subunit: a role for SPOUT methyltransferases in protein arginine methylation. Biochemistry 2012; 51:5091-104. [PMID: 22650761 DOI: 10.1021/bi300186g] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have characterized the posttranslational methylation of Rps2, Rps3, and Rps27a, three small ribosomal subunit proteins in the yeast Saccharomyces cerevisiae, using mass spectrometry and amino acid analysis. We found that Rps2 is substoichiometrically modified at arginine-10 by the Rmt1 methyltransferase. We demonstrated that Rps3 is stoichiometrically modified by ω-monomethylation at arginine-146 by mass spectrometric and site-directed mutagenic analyses. Substitution of alanine for arginine at position 146 is associated with slow cell growth, suggesting that the amino acid identity at this site may influence ribosomal function and/or biogenesis. Analysis of the three-dimensional structure of Rps3 in S. cerevisiae shows that arginine-146 makes contacts with the small subunit rRNA. Screening of deletion mutants encoding potential yeast methyltransferases revealed that the loss of the YOR021C gene results in the absence of methylation of Rps3. We demonstrated that recombinant Yor021c catalyzes ω-monomethylarginine formation when incubated with S-adenosylmethionine and hypomethylated ribosomes prepared from a YOR021C deletion strain. Interestingly, Yor021c belongs to the family of SPOUT methyltransferases that, to date, have only been shown to modify RNA substrates. Our findings suggest a wider role for SPOUT methyltransferases in nature. Finally, we have demonstrated the presence of a stoichiometrically methylated cysteine residue at position 39 of Rps27a in a zinc-cysteine cluster. The discovery of these three novel sites of protein modification within the small ribosomal subunit will now allow for an analysis of their functional roles in translation and possibly other cellular processes.
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Affiliation(s)
- Brian D Young
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095, USA
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Computer-based annotation of putative AraC/XylS-family transcription factors of known structure but unknown function. J Biomed Biotechnol 2012; 2012:103132. [PMID: 22505803 PMCID: PMC3312330 DOI: 10.1155/2012/103132] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/09/2011] [Accepted: 12/13/2011] [Indexed: 12/12/2022] Open
Abstract
Currently, about 20 crystal structures per day are released and deposited in the Protein Data Bank. A significant fraction of these structures is produced by research groups associated with the structural genomics consortium. The biological function of many of these proteins is generally unknown or not validated by experiment. Therefore, a growing need for functional prediction of protein structures has emerged. Here we present an integrated bioinformatics method that combines sequence-based relationships and three-dimensional (3D) structural similarity of transcriptional regulators with computer prediction of their cognate DNA binding sequences. We applied this method to the AraC/XylS family of transcription factors, which is a large family of transcriptional regulators found in many bacteria controlling the expression of genes involved in diverse biological functions. Three putative new members of this family with known 3D structure but unknown function were identified for which a probable functional classification is provided. Our bioinformatics analyses suggest that they could be involved in plant cell wall degradation (Lin2118 protein from Listeria innocua, PDB code 3oou), symbiotic nitrogen fixation (protein from Chromobacterium violaceum, PDB code 3oio), and either metabolism of plant-derived biomass or nitrogen fixation (protein from Rhodopseudomonas palustris, PDB code 3mn2).
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Buck HM. DNA systems for B-Z transition and their significance as epigenetic model: the fundamental role of the methyl group. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2012; 30:918-44. [PMID: 22060556 DOI: 10.1080/15257770.2011.620580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Epigenetic systems involved in the dynamics of gene expression, which are fundamental to cell determination and function without alteration in DNA sequences, are based on methylation of the N-terminal tails of lysine residues and DNA methylation. We demonstrate the vital importance for genetic transfer by different (hydrogen) networks, suggesting a complex interaction between the two epigenetic modifications. In other words, the methylation of local lysines can prescribe C(P)G methylation, which requires that methylation of histones and DNA are cooperative in carrying out an epigenetic instruction for integrating gene-silencing networks. To give a bio-organic description of the epigenetic coherence between histone and base methylation, we used the well-known B- into Z-DNA dynamics in combination with the unique properties of phosphatemethylated DNA on different levels of chemistry.
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40
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Isaac M, Latour JM, Sénèque O. Nucleophilic reactivity of Zinc-bound thiolates: subtle interplay between coordination set and conformational flexibility. Chem Sci 2012. [DOI: 10.1039/c2sc21029k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Zhang L, Ding X, Cui J, Xu H, Chen J, Gong YN, Hu L, Zhou Y, Ge J, Lu Q, Liu L, Chen S, Shao F. Cysteine methylation disrupts ubiquitin-chain sensing in NF-κB activation. Nature 2011; 481:204-8. [PMID: 22158122 DOI: 10.1038/nature10690] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Accepted: 10/28/2011] [Indexed: 12/25/2022]
Abstract
NF-κB is crucial for innate immune defence against microbial infection. Inhibition of NF-κB signalling has been observed with various bacterial infections. The NF-κB pathway critically requires multiple ubiquitin-chain signals of different natures. The question of whether ubiquitin-chain signalling and its specificity in NF-κB activation are regulated during infection, and how this regulation takes place, has not been explored. Here we show that human TAB2 and TAB3, ubiquitin-chain sensory proteins involved in NF-κB signalling, are directly inactivated by enteropathogenic Escherichia coli NleE, a conserved bacterial type-III-secreted effector responsible for blocking host NF-κB signalling. NleE harboured an unprecedented S-adenosyl-l-methionine-dependent methyltransferase activity that specifically modified a zinc-coordinating cysteine in the Npl4 zinc finger (NZF) domains in TAB2 and TAB3. Cysteine-methylated TAB2-NZF and TAB3-NZF (truncated proteins only comprising the NZF domain) lost the zinc ion as well as the ubiquitin-chain binding activity. Ectopically expressed or type-III-secretion-system-delivered NleE methylated TAB2 and TAB3 in host cells and diminished their ubiquitin-chain binding activity. Replacement of the NZF domain of TAB3 with the NleE methylation-insensitive Npl4 NZF domain resulted in NleE-resistant NF-κB activation. Given the prevalence of zinc-finger motifs and activation of cysteine thiol by zinc binding, methylation of zinc-finger cysteine might regulate other eukaryotic pathways in addition to NF-κB signalling.
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Affiliation(s)
- Li Zhang
- Graduate Program in Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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Fuente IMDL, Cortes JM, Perez-Pinilla MB, Ruiz-Rodriguez V, Veguillas J. The metabolic core and catalytic switches are fundamental elements in the self-regulation of the systemic metabolic structure of cells. PLoS One 2011; 6:e27224. [PMID: 22125607 PMCID: PMC3220688 DOI: 10.1371/journal.pone.0027224] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 10/12/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a metabolic core formed by a set of enzymatic reactions which are always active under all environmental conditions, while the rest of catalytic processes are only intermittently active. The reactions of the metabolic core are essential for biomass formation and to assure optimal metabolic performance. The on-off catalytic reactions and the metabolic core are essential elements of a Systemic Metabolic Structure which seems to be a key feature common to all cellular organisms. METHODOLOGY/PRINCIPAL FINDINGS In order to investigate the functional importance of the metabolic core we have studied different catalytic patterns of a dissipative metabolic network under different external conditions. The emerging biochemical data have been analysed using information-based dynamic tools, such as Pearson's correlation and Transfer Entropy (which measures effective functionality). Our results show that a functional structure of effective connectivity emerges which is dynamical and characterized by significant variations of bio-molecular information flows. CONCLUSIONS/SIGNIFICANCE We have quantified essential aspects of the metabolic core functionality. The always active enzymatic reactions form a hub--with a high degree of effective connectivity--exhibiting a wide range of functional information values being able to act either as a source or as a sink of bio-molecular causal interactions. Likewise, we have found that the metabolic core is an essential part of an emergent functional structure characterized by catalytic modules and metabolic switches which allow critical transitions in enzymatic activity. Both, the metabolic core and the catalytic switches in which also intermittently-active enzymes are involved seem to be fundamental elements in the self-regulation of the Systemic Metabolic Structure.
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43
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Lee YM, Lim C. Factors Controlling the Reactivity of Zinc Finger Cores. J Am Chem Soc 2011; 133:8691-703. [DOI: 10.1021/ja202165x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yu-Ming Lee
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Carmay Lim
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
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Pegg AE. Multifaceted roles of alkyltransferase and related proteins in DNA repair, DNA damage, resistance to chemotherapy, and research tools. Chem Res Toxicol 2011; 24:618-39. [PMID: 21466232 DOI: 10.1021/tx200031q] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
O(6)-Alkylguanine-DNA alkyltransferase (AGT) is a widely distributed, unique DNA repair protein that acts as a single agent to directly remove alkyl groups located on the O(6)-position of guanine from DNA restoring the DNA in one step. The protein acts only once, and its alkylated form is degraded rapidly. It is a major factor in counteracting the mutagenic, carcinogenic, and cytotoxic effects of agents that form such adducts including N-nitroso-compounds and a number of cancer chemotherapeutics. This review describes the structure, function, and mechanism of action of AGTs and of a family of related alkyltransferase-like proteins, which do not act alone to repair O(6)-alkylguanines in DNA but link repair to other pathways. The paradoxical ability of AGTs to stimulate the DNA-damaging ability of dihaloalkanes and other bis-electrophiles via the formation of AGT-DNA cross-links is also described. Other important properties of AGTs include the ability to provide resistance to cancer therapeutic alkylating agents, and the availability of AGT inhibitors such as O(6)-benzylguanine that might overcome this resistance is discussed. Finally, the properties of fusion proteins in which AGT sequences are linked to other proteins are outlined. Such proteins occur naturally, and synthetic variants engineered to react specifically with derivatives of O(6)-benzylguanine are the basis of a valuable research technique for tagging proteins with specific reagents.
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Affiliation(s)
- Anthony E Pegg
- Department of Cellular and Molecular Physiology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine , Pennsylvania 17033, United States.
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45
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Quintal SM, dePaula QA, Farrell NP. Zinc finger proteins as templates for metal ion exchange and ligand reactivity. Chemical and biological consequences. Metallomics 2011; 3:121-39. [PMID: 21253649 DOI: 10.1039/c0mt00070a] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Zinc finger reactions with inorganic ions and coordination compounds are as diverse as the zinc fingers themselves. Use of metal ions such as Co(2+) and Cd(2+) has given structural, thermodynamic and kinetic information on zinc fingers and zinc-finger-DNA/RNA interactions. It is a general truism that alteration of the coordination sphere in the finger environment will disrupt the recognition with DNA/RNA and this has implications for mechanism of toxicity and carcinogenesis of metal ions. Structural zinc fingers are susceptible to electrophilic attack and the recognition that the coordination sphere of inorganic compounds may be modulated for control of electrophilic attack on zinc fingers raises the possibility of systematic studies of zinc fingers as drug targets using inorganic chemistry. Some inorganic compounds such as those of As(III) and Au(I) may exert their biological effects through inactivation of zinc fingers and novel approaches to specifically attack the zinc-bound ligands using Co(III)-Schiff bases and Platinum(II)-Nucleobase compounds have been proposed. The genomic importance of zinc fingers suggests that the "coordination chemistry" of zinc fingers themselves is ripe for exploration to design new targets for medicinal inorganic chemistry.
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Affiliation(s)
- Susana M Quintal
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main St., Richmond, VA 23284-2006, USA
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46
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Jones GDD, Le Pla RC, Farmer PB. Phosphotriester adducts (PTEs): DNA's overlooked lesion. Mutagenesis 2009; 25:3-16. [DOI: 10.1093/mutage/gep038] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Shrivastav N, Li D, Essigmann JM. Chemical biology of mutagenesis and DNA repair: cellular responses to DNA alkylation. Carcinogenesis 2009; 31:59-70. [PMID: 19875697 DOI: 10.1093/carcin/bgp262] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The reaction of DNA-damaging agents with the genome results in a plethora of lesions, commonly referred to as adducts. Adducts may cause DNA to mutate, they may represent the chemical precursors of lethal events and they can disrupt expression of genes. Determination of which adduct is responsible for each of these biological endpoints is difficult, but this task has been accomplished for some carcinogenic DNA-damaging agents. Here, we describe the respective contributions of specific DNA lesions to the biological effects of low molecular weight alkylating agents.
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Affiliation(s)
- Nidhi Shrivastav
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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48
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Dalhus B, Laerdahl JK, Backe PH, Bjørås M. DNA base repair--recognition and initiation of catalysis. FEMS Microbiol Rev 2009; 33:1044-78. [PMID: 19659577 DOI: 10.1111/j.1574-6976.2009.00188.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Endogenous DNA damage induced by hydrolysis, reactive oxygen species and alkylation modifies DNA bases and the structure of the DNA duplex. Numerous mechanisms have evolved to protect cells from these deleterious effects. Base excision repair is the major pathway for removing base lesions. However, several mechanisms of direct base damage reversal, involving enzymes such as transferases, photolyases and oxidative demethylases, are specialized to remove certain types of photoproducts and alkylated bases. Mismatch excision repair corrects for misincorporation of bases by replicative DNA polymerases. The determination of the 3D structure and visualization of DNA repair proteins and their interactions with damaged DNA have considerably aided our understanding of the molecular basis for DNA base lesion repair and genome stability. Here, we review the structural biochemistry of base lesion recognition and initiation of one-step direct reversal (DR) of damage as well as the multistep pathways of base excision repair (BER), nucleotide incision repair (NIR) and mismatch repair (MMR).
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Affiliation(s)
- Bjørn Dalhus
- Centre for Molecular Biology and Neuroscience (CMBN), Rikshospitalet University Hospital, Oslo, Norway
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Nguyen TTH, Eiamphungporn W, Mäder U, Liebeke M, Lalk M, Hecker M, Helmann JD, Antelmann H. Genome-wide responses to carbonyl electrophiles in Bacillus subtilis: control of the thiol-dependent formaldehyde dehydrogenase AdhA and cysteine proteinase YraA by the MerR-family regulator YraB (AdhR). Mol Microbiol 2008; 71:876-94. [PMID: 19170879 DOI: 10.1111/j.1365-2958.2008.06568.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Quinones and alpha,beta-unsaturated carbonyls are naturally occurring electrophiles that target cysteine residues via thiol-(S)-alkylation. We analysed the global expression profile of Bacillus subtilis to the toxic carbonyls methylglyoxal (MG) and formaldehyde (FA). Both carbonyl compounds cause a stress response characteristic for thiol-reactive electrophiles as revealed by the induction of the Spx, CtsR, CymR, PerR, ArsR, CzrA, CsoR and SigmaD regulons. MG and FA triggered also a SOS response which indicates DNA damage. Protection against FA is mediated by both the hxlAB operon, encoding the ribulose monophosphate pathway for FA fixation, and a thiol-dependent formaldehyde dehydrogenase (AdhA) and DJ-1/PfpI-family cysteine proteinase (YraA). The adhA-yraA operon and the yraC gene, encoding a gamma-carboxymuconolactone decarboxylase, are positively regulated by the MerR-family regulator, YraB(AdhR). AdhR binds specifically to its target promoters which contain a 7-4-7 inverted repeat (CTTAAAG-N4-CTTTAAG) between the -35 and -10 elements. Activation of adhA-yraA transcription by AdhR requires the conserved Cys52 residue in vivo. We speculate that AdhR is redox-regulated via thiol-(S)-alkylation by aldehydes and that AdhA and YraA are specifically involved in reduction of aldehydes and degradation or repair of damaged thiol-containing proteins respectively.
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Affiliation(s)
- Thi Thu Huyen Nguyen
- Institute for Microbiology, Ernst-Moritz-Arndt-University of Greifswald, D-17487 Greifswald, Germany
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Abstract
Bacterial gene regulators containing transition metal cofactors that function as binding sites for small ligands were first described in the 1990s. Since then, numerous metal-containing regulators have been discovered, and our knowledge of the diversity of proteins, their cofactors and the signals that they sense has greatly increased. The present article reviews recent developments, with a particular focus on bacterial sensors of nitric oxide.
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