1
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Ge S, Zhang B. Analysis of the effect of pulsed light on the protein of Lactobacillus plantarum based on liquid mass spectrometry. Food Sci Biotechnol 2024; 33:617-624. [PMID: 38274179 PMCID: PMC10805731 DOI: 10.1007/s10068-023-01365-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/02/2023] [Accepted: 06/06/2023] [Indexed: 01/27/2024] Open
Abstract
Studying the mutagenesis mechanism is crucial for pulsed light use in the food processing industry. After being exposed to pulsed light, the original strain Y Lactobacillus Plantarum CICC6048 was transformed into the high acid-producing mutant G10. The differing levels of protein expression between the two strains were compared using the LC-MS/MS analysis. The bacterium displayed a distinct differential protein composition after pulsed light treatment, according to GO analysis. A KEGG analysis revealed that the pathways for cofactor biosynthesis, starch, sucrose metabolism, and phosphate transfer systems were considerably different in the proteins of high acid-producing strains (PTS). In the protein interaction network, A0A0R2G2S1 showed the highest level of enhanced connectivity among the differentially expressed proteins. These pathways improve the efficiency of crucial metabolism and lessen DNA repair. They may be a key mechanism for increasing the growth rate and acid production of Lactobacillus Plantarum by pulsed light.
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Affiliation(s)
- Shanying Ge
- College of Food Science, Shenyang Agricultural University, Shenyang, China
| | - Baiqing Zhang
- College of Food Science, Shenyang Agricultural University, Shenyang, China
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2
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He F, Bravo M, Fan L. Helicases required for nucleotide excision repair: structure, function and mechanism. Enzymes 2023; 54:273-304. [PMID: 37945175 DOI: 10.1016/bs.enz.2023.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Nucleotide excision repair (NER) is a major DNA repair pathway conserved from bacteria to humans. Various DNA helicases, a group of enzymes capable of separating DNA duplex into two strands through ATP binding and hydrolysis, are required by NER to unwind the DNA duplex around the lesion to create a repair bubble and for damage verification and removal. In prokaryotes, UvrB helicase is required for repair bubble formation and damage verification, while UvrD helicase is responsible for the removal of the excised damage containing single-strand (ss) DNA fragment. In addition, UvrD facilitates transcription-coupled repair (TCR) by backtracking RNA polymerase stalled at the lesion. In eukaryotes, two helicases XPB and XPD from the transcription factor TFIIH complex fulfill the helicase requirements of NER. Interestingly, homologs of all these four helicases UvrB, UvrD, XPB, and XPD have been identified in archaea. This review summarizes our current understanding about the structure, function, and mechanism of these four helicases.
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Affiliation(s)
- Feng He
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, United States
| | - Marco Bravo
- Department of Biochemistry, University of California, Riverside, CA, United States
| | - Li Fan
- Department of Biochemistry, University of California, Riverside, CA, United States.
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3
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Najjari A, Boussetta A, Youssef N, Linares-Pastén JA, Mahjoubi M, Belloum R, Sghaier H, Cherif A, Ouzari HI. Physiological and genomic insights into abiotic stress of halophilic archaeon Natrinema altunense 4.1R isolated from a saline ecosystem of Tunisian desert. Genetica 2023; 151:133-152. [PMID: 36795306 PMCID: PMC9995536 DOI: 10.1007/s10709-023-00182-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 02/02/2023] [Indexed: 02/17/2023]
Abstract
Halophilic archaea are polyextremophiles with the ability to withstand fluctuations in salinity, high levels of ultraviolet radiation, and oxidative stress, allowing them to survive in a wide range of environments and making them an excellent model for astrobiological research. Natrinema altunense 4.1R is a halophilic archaeon isolated from the endorheic saline lake systems, Sebkhas, located in arid and semi-arid regions of Tunisia. It is an ecosystem characterized by periodic flooding from subsurface groundwater and fluctuating salinities. Here, we assess the physiological responses and genomic characterization of N. altunense 4.1R to UV-C radiation, as well as osmotic and oxidative stresses. Results showed that the 4.1R strain is able to survive up to 36% of salinity, up to 180 J/m2 to UV-C radiation, and at 50 mM of H2O2, a resistance profile similar to Halobacterium salinarum, a strain often used as UV-C resistant model. In order to understand the genetic determinants of N. altunense 4.1R survival strategy, we sequenced and analyzed its genome. Results showed multiple gene copies of osmotic stress, oxidative stress, and DNA repair response mechanisms supporting its survivability at extreme salinities and radiations. Indeed, the 3D molecular structures of seven proteins related to responses to UV-C radiation (excinucleases UvrA, UvrB, and UvrC, and photolyase), saline stress (trehalose-6-phosphate synthase OtsA and trehalose-phosphatase OtsB), and oxidative stress (superoxide dismutase SOD) were constructed by homology modeling. This study extends the abiotic stress range for the species N. altunense and adds to the repertoire of UV and oxidative stress resistance genes generally known from haloarchaeon.
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Affiliation(s)
- Afef Najjari
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092, Tunis, Tunisie
| | - Ayoub Boussetta
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092, Tunis, Tunisie
| | - Noha Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Javier A Linares-Pastén
- Department of Biotechnology, Faculty of Engineering, Lunds Tekniska Högskola (LTH), Lund University, P. O. Box 124, 22100, Lund, Sweden.
| | - Mouna Mahjoubi
- University of Manouba, ISBST, LR11-ES31 BVBGR, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Rahma Belloum
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092, Tunis, Tunisie
| | - Haitham Sghaier
- Laboratory "Energy and Matter for Development of Nuclear Sciences" (LR16CNSTN02), National Center for Nuclear Sciences and Technology (CNSTN), Ariana, Tunisia
| | - Ameur Cherif
- University of Manouba, ISBST, LR11-ES31 BVBGR, Biotechpole Sidi Thabet, 2020, Ariana, Tunisia
| | - Hadda Imene Ouzari
- Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Université Tunis El Manar, 2092, Tunis, Tunisie
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4
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Singh PR, Gupta A, Rajneesh, Pathak J, Sinha RP. Phylogenetic distribution, structural analysis and interaction of nucleotide excision repair proteins in cyanobacteria. DNA Repair (Amst) 2023; 126:103487. [PMID: 37054651 DOI: 10.1016/j.dnarep.2023.103487] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 03/25/2023] [Accepted: 03/26/2023] [Indexed: 03/30/2023]
Abstract
Cyanobacteria are photosynthetic Gram-negative, oxygen evolving prokaryotes with cosmopolitan distribution. Ultraviolet radiation (UVR) and other abiotic stresses result in DNA lesions in cyanobacteria. Nucleotide excision repair (NER) pathway removes the DNA lesions produced by UVR to normal DNA sequence. In cyanobacteria, detailed knowledge about NER proteins is poorly studied. Therefore, we have studied the NER proteins in cyanobacteria. Analyses of 289 amino acids sequence from 77 cyanobacterial species have revealed the presence of a minimum of one copy of NER protein in their genome. Phylogenetic analysis of NER protein shows that UvrD has maximal rate of amino acid substitutions which resulted in increased branch length. The motif analysis shows that UvrABC proteins is more conserved than UvrD, Further, UvrA with UvrB protein interacts with each other and form stable complex which have DNA binding domain on the surface of the complex. UvrB also have DNA binding domain. Positive electrostatic potential was found in the DNA binding region, which is followed by negative and neutral electrostatic potential. Additionally, the surface accessibility values at the DNA strands of T5-T6 dimer binding site were maximal. Protein nucleotide interaction shows the strong binding of T5-T6 dimer with NER proteins of Synechocystis sp. PCC 6803. This process repairs the UV-induced DNA lesions in dark when photoreactivation is inactive. Regulation of NER proteins protect cyanobacterial genome and maintain the fitness of organism under different abiotic stresses.
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5
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Thakur M, Muniyappa K. Macrophage activation highlight an important role for NER proteins in the survival, latency and multiplication of Mycobacterium tuberculosis. Tuberculosis (Edinb) 2023; 138:102284. [PMID: 36459831 DOI: 10.1016/j.tube.2022.102284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/14/2022] [Accepted: 11/20/2022] [Indexed: 11/27/2022]
Abstract
Nucleotide excision repair (NER) is one of the most extensively studied DNA repair processes in both prokaryotes and eukaryotes. The NER pathway is a highly conserved, ATP-dependent multi-step process involving several proteins/enzymes that function in a concerted manner to recognize and excise a wide spectrum of helix-distorting DNA lesions and bulky adducts by nuclease cleavage on either side of the damaged bases. As such, the NER pathway of Mycobacterium tuberculosis (Mtb) is essential for its survival within the hostile environment of macrophages and disease progression. This review focuses on present published knowledge about the crucial roles of Mtb NER proteins in the survival and multiplication of the pathogen within the macrophages and as potential targets for drug discovery.
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Affiliation(s)
- Manoj Thakur
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India.
| | - K Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India
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6
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Kaur R, Nikkel DJ, Aboelnga MM, Wetmore SD. The Impact of DFT Functional, Cluster Model Size, and Implicit Solvation on the Structural Description of Single-Metal-Mediated DNA Phosphodiester Bond Cleavage: The Case Study of APE1. J Phys Chem B 2022; 126:10672-10683. [PMID: 36485014 DOI: 10.1021/acs.jpcb.2c06756] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Phosphodiester bond hydrolysis in nucleic acids is a ubiquitous reaction that can be facilitated by enzymes called nucleases, which often use metal ions to achieve catalytic function. While a two-metal-mediated pathway has been well established for many enzymes, there is growing support that some enzymes require only one metal for the catalytic step. Using human apurinic/apyrimidinic endonuclease (APE1) as a prototypical example and cluster models, this study clarifies the impact of DFT functional, cluster model size, and implicit solvation on single-metal-mediated phosphodiester bond cleavage and provides insight into how to efficiently model this chemistry. Initially, a model containing 69 atoms built from a high-resolution X-ray crystal structure is used to explore the reaction pathway mapped by a range of DFT functionals and basis sets, which provides support for the use of standard functionals (M06-2X and B3LYP-D3) to study this reaction. Subsequently, systematically increasing the model size to 185 atoms by including additional amino acids and altering residue truncation points highlights that small models containing only a few amino acids or β carbon truncation points introduce model strains and lead to incorrect metal coordination. Indeed, a model that contains all key residues (general base and acid, residues that stabilize the substrate, and amino acids that maintain the metal coordination) is required for an accurate structural depiction of the one-metal-mediated phosphodiester bond hydrolysis by APE1, which results in 185 atoms. The additional inclusion of the broader enzyme environment through continuum solvation models has negligible effects. The insights gained in the present work can be used to direct future computational studies of other one-metal-dependent nucleases to provide a greater understanding of how nature achieves this difficult chemistry.
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Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Dylan J Nikkel
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Mohamed M Aboelnga
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada.,Chemistry Department, Faculty of Science, Damietta University, New Damietta 34517, Egypt
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
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7
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The Helicobacter pylori UvrC Nuclease Is Essential for Chromosomal Microimports after Natural Transformation. mBio 2022; 13:e0181122. [PMID: 35876509 PMCID: PMC9426483 DOI: 10.1128/mbio.01811-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Helicobacter pylori is a Gram-negative bacterial carcinogenic pathogen that infects the stomachs of half of the human population. It is a natural mutator due to a deficient DNA mismatch repair pathway and is naturally competent for transformation. As a result, it is one of the most genetically diverse human bacterial pathogens. The length of chromosomal imports in H. pylori follows an unusual bimodal distribution consisting of macroimports with a mean length of 1,645 bp and microimports with a mean length of 28 bp. The mechanisms responsible for this import pattern were unknown. Here, we used a high-throughput whole-genome transformation assay to elucidate the role of nucleotide excision repair pathway (NER) components on import length distribution. The data show that the integration of microimports depended on the activity of the UvrC endonuclease, while none of the other components of the NER pathway was required. Using H. pylori site-directed mutants, we showed that the widely conserved UvrC nuclease active sites, while essential for protection from UV light, one of the canonical NER functions, are not required for generation of microimports. A quantitative analysis of recombination patterns based on over 1,000 imports from over 200 sequenced recombinant genomes showed that microimports occur frequently within clusters of multiple imports, strongly suggesting they derive from a single strand invasion event. We propose a hypothetical model of homologous recombination in H. pylori, involving a novel function of UvrC, that reconciles the available experimental data about recombination patterns in H. pylori. IMPORTANCE Helicobacter pylori is one of the most common and genetically diverse human bacterial pathogens. It is responsible for chronic gastritis and represents the main risk factor for gastric cancer. In H. pylori, DNA fragments can be imported by recombination during natural transformation. The length of those fragments determines how many potentially beneficial or deleterious alleles are acquired and thus influences adaptation to the gastric niche. Here, we used a transformation assay to examine imported fragments across the chromosome. We show that UvrC, an endonuclease involved in DNA repair, is responsible for the specific integration of short DNA fragments. This suggests that short and long fragments are imported through distinct recombination pathways. We also show that short fragments are frequently clustered with longer fragments, suggesting that both pathways may be mechanistically linked. These findings provide a novel basis to explain how H. pylori can fine-tune the genetic diversity acquired by transformation.
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8
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Verma P, Kumari P, Negi S, Yadav G, Gaur V. Holliday junction resolution by At-HIGLE: an SLX1 lineage endonuclease from Arabidopsis thaliana with a novel in-built regulatory mechanism. Nucleic Acids Res 2022; 50:4630-4646. [PMID: 35412622 PMCID: PMC9071465 DOI: 10.1093/nar/gkac239] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/24/2022] [Accepted: 04/01/2022] [Indexed: 12/14/2022] Open
Abstract
Holliday junction is the key homologous recombination intermediate, resolved by structure-selective endonucleases (SSEs). SLX1 is the most promiscuous SSE of the GIY-YIG nuclease superfamily. In fungi and animals, SLX1 nuclease activity relies on a non-enzymatic partner, SLX4, but no SLX1-SLX4 like complex has ever been characterized in plants. Plants exhibit specialized DNA repair and recombination machinery. Based on sequence similarity with the GIY-YIG nuclease domain of SLX1 proteins from fungi and animals, At-HIGLE was identified to be a possible SLX1 like nuclease from plants. Here, we elucidated the crystal structure of the At-HIGLE nuclease domain from Arabidopsis thaliana, establishing it as a member of the SLX1-lineage of the GIY-YIG superfamily with structural changes in DNA interacting regions. We show that At-HIGLE can process branched-DNA molecules without an SLX4 like protein. Unlike fungal SLX1, At-HIGLE exists as a catalytically active homodimer capable of generating two coordinated nicks during HJ resolution. Truncating the extended C-terminal region of At-HIGLE increases its catalytic activity, changes the nicking pattern, and monomerizes At-HIGLE. Overall, we elucidated the first structure of a plant SLX1-lineage protein, showed its HJ resolving activity independent of any regulatory protein, and identified an in-built novel regulatory mechanism engaging its C-terminal region.
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Affiliation(s)
- Prabha Verma
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Poonam Kumari
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Shreya Negi
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Gitanjali Yadav
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Vineet Gaur
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
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9
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In vitro reconstitution of an efficient nucleotide excision repair system using mesophilic enzymes from Deinococcus radiodurans. Commun Biol 2022; 5:127. [PMID: 35149830 PMCID: PMC8837605 DOI: 10.1038/s42003-022-03064-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/18/2022] [Indexed: 11/08/2022] Open
Abstract
Nucleotide excision repair (NER) is a universal and versatile DNA repair pathway, capable of removing a very wide range of lesions, including UV-induced pyrimidine dimers and bulky adducts. In bacteria, NER involves the sequential action of the UvrA, UvrB and UvrC proteins to release a short 12- or 13-nucleotide DNA fragment containing the damaged site. Although bacterial NER has been the focus of numerous studies over the past 40 years, a number of key questions remain unanswered regarding the mechanisms underlying DNA damage recognition by UvrA, the handoff to UvrB and the site-specific incision by UvrC. In the present study, we have successfully reconstituted in vitro a robust NER system using the UvrABC proteins from the radiation resistant bacterium, Deinococcus radiodurans. We have investigated the influence of various parameters, including temperature, salt, protein and ATP concentrations, protein purity and metal cations, on the dual incision by UvrABC, so as to find the optimal conditions for the efficient release of the short lesion-containing oligonucleotide. This newly developed assay relying on the use of an original, doubly-labelled DNA substrate has allowed us to probe the kinetics of repair on different DNA substrates and to determine the order and precise sites of incisions on the 5′ and 3′ sides of the lesion. This new assay thus constitutes a valuable tool to further decipher the NER pathway in bacteria. Reconstitution of D radiodurans nucleotide excision repair provides insights into the kinetics of repair on different DNA substrates and determines the order and precise sites of incisions on the 5’ and 3’ sides of the lesion.
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10
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Schaich MA, Van Houten B. Searching for DNA Damage: Insights From Single Molecule Analysis. Front Mol Biosci 2021; 8:772877. [PMID: 34805281 PMCID: PMC8602339 DOI: 10.3389/fmolb.2021.772877] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/18/2021] [Indexed: 01/26/2023] Open
Abstract
DNA is under constant threat of damage from a variety of chemical and physical insults, such as ultraviolet rays produced by sunlight and reactive oxygen species produced during respiration or inflammation. Because damaged DNA, if not repaired, can lead to mutations or cell death, multiple DNA repair pathways have evolved to maintain genome stability. Two repair pathways, nucleotide excision repair (NER) and base excision repair (BER), must sift through large segments of nondamaged nucleotides to detect and remove rare base modifications. Many BER and NER proteins share a common base-flipping mechanism for the detection of modified bases. However, the exact mechanisms by which these repair proteins detect their damaged substrates in the context of cellular chromatin remains unclear. The latest generation of single-molecule techniques, including the DNA tightrope assay, atomic force microscopy, and real-time imaging in cells, now allows for nearly direct visualization of the damage search and detection processes. This review describes several mechanistic commonalities for damage detection that were discovered with these techniques, including a combination of 3-dimensional and linear diffusion for surveying damaged sites within long stretches of DNA. We also discuss important findings that DNA repair proteins within and between pathways cooperate to detect damage. Finally, future technical developments and single-molecule studies are described which will contribute to the growing mechanistic understanding of DNA damage detection.
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Affiliation(s)
- Matthew A Schaich
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Bennett Van Houten
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Molecular Biophysics and Structural Biology Graduate Program, University of Pittsburgh, Pittsburgh, PA, United States
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Evolutionary Origins of DNA Repair Pathways: Role of Oxygen Catastrophe in the Emergence of DNA Glycosylases. Cells 2021; 10:cells10071591. [PMID: 34202661 PMCID: PMC8307549 DOI: 10.3390/cells10071591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022] Open
Abstract
It was proposed that the last universal common ancestor (LUCA) evolved under high temperatures in an oxygen-free environment, similar to those found in deep-sea vents and on volcanic slopes. Therefore, spontaneous DNA decay, such as base loss and cytosine deamination, was the major factor affecting LUCA’s genome integrity. Cosmic radiation due to Earth’s weak magnetic field and alkylating metabolic radicals added to these threats. Here, we propose that ancient forms of life had only two distinct repair mechanisms: versatile apurinic/apyrimidinic (AP) endonucleases to cope with both AP sites and deaminated residues, and enzymes catalyzing the direct reversal of UV and alkylation damage. The absence of uracil–DNA N-glycosylases in some Archaea, together with the presence of an AP endonuclease, which can cleave uracil-containing DNA, suggests that the AP endonuclease-initiated nucleotide incision repair (NIR) pathway evolved independently from DNA glycosylase-mediated base excision repair. NIR may be a relic that appeared in an early thermophilic ancestor to counteract spontaneous DNA damage. We hypothesize that a rise in the oxygen level in the Earth’s atmosphere ~2 Ga triggered the narrow specialization of AP endonucleases and DNA glycosylases to cope efficiently with a widened array of oxidative base damage and complex DNA lesions.
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12
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Kraithong T, Hartley S, Jeruzalmi D, Pakotiprapha D. A Peek Inside the Machines of Bacterial Nucleotide Excision Repair. Int J Mol Sci 2021; 22:ijms22020952. [PMID: 33477956 PMCID: PMC7835731 DOI: 10.3390/ijms22020952] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/13/2022] Open
Abstract
Double stranded DNA (dsDNA), the repository of genetic information in bacteria, archaea and eukaryotes, exhibits a surprising instability in the intracellular environment; this fragility is exacerbated by exogenous agents, such as ultraviolet radiation. To protect themselves against the severe consequences of DNA damage, cells have evolved at least six distinct DNA repair pathways. Here, we review recent key findings of studies aimed at understanding one of these pathways: bacterial nucleotide excision repair (NER). This pathway operates in two modes: a global genome repair (GGR) pathway and a pathway that closely interfaces with transcription by RNA polymerase called transcription-coupled repair (TCR). Below, we discuss the architecture of key proteins in bacterial NER and recent biochemical, structural and single-molecule studies that shed light on the lesion recognition steps of both the GGR and the TCR sub-pathways. Although a great deal has been learned about both of these sub-pathways, several important questions, including damage discrimination, roles of ATP and the orchestration of protein binding and conformation switching, remain to be addressed.
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Affiliation(s)
- Thanyalak Kraithong
- Doctor of Philosophy Program in Biochemistry (International Program), Faculty of Science, Mahidol University, Bangkok 10400, Thailand;
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Silas Hartley
- Department of Chemistry and Biochemistry, City College of New York, New York, NY 10031, USA;
- Doctor of Philosophy Programs in Biochemistry, Biology and Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - David Jeruzalmi
- Department of Chemistry and Biochemistry, City College of New York, New York, NY 10031, USA;
- Doctor of Philosophy Programs in Biochemistry, Biology and Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
- Correspondence: (D.J.); (D.P.)
| | - Danaya Pakotiprapha
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (D.J.); (D.P.)
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13
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Thakur M, Agarwal A, Muniyappa K. The intrinsic ATPase activity of Mycobacterium tuberculosis UvrC is crucial for its damage-specific DNA incision function. FEBS J 2020; 288:1179-1200. [PMID: 32602194 DOI: 10.1111/febs.15465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 05/04/2020] [Accepted: 06/24/2020] [Indexed: 11/28/2022]
Abstract
To ensure genome stability, bacteria have evolved a network of DNA repair mechanisms; among them, the UvrABC-dependent nucleotide excision repair (NER) pathway is essential for the incision of a variety of bulky adducts generated by exogenous chemicals, UV radiation and by-products of cellular metabolism. However, very little is known about the enzymatic properties of Mycobacterium tuberculosis UvrABC excinuclease complex. Furthermore, the biochemical properties of Escherichia coli UvrC (EcUvrC) are not well understood (compared to UvrA and UvrB), perhaps due to its limited availability and/or activity instability in vitro. In addition, homology modelling of M. tuberculosis UvrC (MtUvrC) revealed the presence of a putative ATP-binding pocket, although its function remains unknown. To elucidate the biochemical properties of UvrC, we constructed and purified wild-type MtUvrC and its eight variants harbouring mutations within the ATP-binding pocket. The data from DNA-binding studies suggest that MtUvrC exhibits high-affinity for duplex DNA containing a bubble or fluorescein-dT moiety, over fluorescein-adducted single-stranded DNA. Most notably, MtUvrC has an intrinsic UvrB-independent ATPase activity, which drives dual incision of the damaged DNA strand. In contrast, EcUvrC is devoid of ATPase activity; however, it retains the ability to bind ATP at levels comparable to that of MtUvrC. The ATPase-deficient variants map to residues lining the MtUvrC ATP-binding pocket. Further analysis of these variants revealed separation of function between ATPase and DNA-binding activities in MtUvrC. Altogether, these findings reveal functional diversity of the bacterial NER machinery and a paradigm for the evolution of a catalytic scaffold in UvrC.
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Affiliation(s)
- Manoj Thakur
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Ankit Agarwal
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
| | - Kalappa Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, India
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14
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Silva RMB, Grodick MA, Barton JK. UvrC Coordinates an O 2-Sensitive [4Fe4S] Cofactor. J Am Chem Soc 2020; 142:10964-10977. [PMID: 32470300 DOI: 10.1021/jacs.0c01671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent advances have led to numerous landmark discoveries of [4Fe4S] clusters coordinated by essential enzymes in repair, replication, and transcription across all domains of life. The cofactor has notably been challenging to observe for many nucleic acid processing enzymes due to several factors, including a weak bioinformatic signature of the coordinating cysteines and lability of the metal cofactor. To overcome these challenges, we have used sequence alignments, an anaerobic purification method, iron quantification, and UV-visible and electron paramagnetic resonance spectroscopies to investigate UvrC, the dual-incision endonuclease in the bacterial nucleotide excision repair (NER) pathway. The characteristics of UvrC are consistent with [4Fe4S] coordination with 60-70% cofactor incorporation, and additionally, we show that, bound to UvrC, the [4Fe4S] cofactor is susceptible to oxidative degradation with aggregation of apo species. Importantly, in its holo form with the cofactor bound, UvrC forms high affinity complexes with duplexed DNA substrates; the apparent dissociation constants to well-matched and damaged duplex substrates are 100 ± 20 nM and 80 ± 30 nM, respectively. This high affinity DNA binding contrasts reports made for isolated protein lacking the cofactor. Moreover, using DNA electrochemistry, we find that the cluster coordinated by UvrC is redox-active and participates in DNA-mediated charge transport chemistry with a DNA-bound midpoint potential of 90 mV vs NHE. This work highlights that the [4Fe4S] center is critical to UvrC.
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Affiliation(s)
- Rebekah M B Silva
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Michael A Grodick
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Jacqueline K Barton
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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15
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Thakur M, Muniyappa K. Deciphering the essentiality and function of SxSx motif in Mycobacterium tuberculosis UvrB. Biochimie 2020; 170:94-105. [PMID: 31923481 DOI: 10.1016/j.biochi.2020.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 01/06/2020] [Indexed: 10/25/2022]
Abstract
The UvrB subunit is a central component of the UvrABC incision complex and plays a pivotal role in damage recognition, strand excision and repair synthesis. A conserved structural motif (the SxSx motif) present in UvrB is analogous to a similar motif (TxGx) in the helicases of superfamily 2, whose function is not fully understood. To elucidate the significance of the SxSx (Ser143-Val144-Ser145-Cys146) motif in Mycobacterium tuberculosis UvrB (MtUvrB), different variants of MtUvrB subunit were constructed and characterized. The SxSx motif indeed was found to be essential for MtUvrB function: while Ser143 and Cys146 residues within this motif were crucial for MtUvrB function, Ser145 plays an important but less essential role. The SxSx motif-deleted mutant was drastically attenuated and three single (S143A, S145A and C146A) mutants and a double (S143A/S145A) mutant exhibited various degrees of severity in their DNA-binding, DNA helicase and ATPase activities. Taken together, these results highlight a hitherto unrecognized role for SxSx motif in the catalytic activities of UvrB.
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Affiliation(s)
- Manoj Thakur
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India
| | - K Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India.
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16
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Case BC, Hartley S, Osuga M, Jeruzalmi D, Hingorani MM. The ATPase mechanism of UvrA2 reveals the distinct roles of proximal and distal ATPase sites in nucleotide excision repair. Nucleic Acids Res 2019; 47:4136-4152. [PMID: 30892613 PMCID: PMC6486640 DOI: 10.1093/nar/gkz180] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/02/2019] [Accepted: 03/18/2019] [Indexed: 01/20/2023] Open
Abstract
The UvrA2 dimer finds lesions in DNA and initiates nucleotide excision repair. Each UvrA monomer contains two essential ATPase sites: proximal (P) and distal (D). The manner whereby their activities enable UvrA2 damage sensing and response remains to be clarified. We report three key findings from the first pre-steady state kinetic analysis of each site. Absent DNA, a P2ATP-D2ADP species accumulates when the low-affinity proximal sites bind ATP and enable rapid ATP hydrolysis and phosphate release by the high-affinity distal sites, and ADP release limits catalytic turnover. Native DNA stimulates ATP hydrolysis by all four sites, causing UvrA2 to transition through a different species, P2ADP-D2ADP. Lesion-containing DNA changes the mechanism again, suppressing ATP hydrolysis by the proximal sites while distal sites cycle through hydrolysis and ADP release, to populate proximal ATP-bound species, P2ATP-Dempty and P2ATP-D2ATP. Thus, damaged and native DNA trigger distinct ATPase site activities, which could explain why UvrA2 forms stable complexes with UvrB on damaged DNA compared with weaker, more dynamic complexes on native DNA. Such specific coupling between the DNA substrate and the ATPase mechanism of each site provides new insights into how UvrA2 utilizes ATP for lesion search, recognition and repair.
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Affiliation(s)
- Brandon C Case
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Silas Hartley
- Department of Chemistry and Biochemistry, City College of New York of the City University of New York, New York, NY 10031, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Memie Osuga
- Department of Chemistry and Biochemistry, City College of New York of the City University of New York, New York, NY 10031, USA.,Hunter College High School, New York, NY 10128, USA
| | - David Jeruzalmi
- Department of Chemistry and Biochemistry, City College of New York of the City University of New York, New York, NY 10031, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA.,Ph.D. Programs in Chemistry and Biology, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Manju M Hingorani
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
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17
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Lee SJ, Sung RJ, Verdine GL. Mechanism of DNA Lesion Homing and Recognition by the Uvr Nucleotide Excision Repair System. RESEARCH (WASHINGTON, D.C.) 2019; 2019:5641746. [PMID: 31549070 PMCID: PMC6750098 DOI: 10.34133/2019/5641746] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 06/26/2019] [Indexed: 11/06/2022]
Abstract
Nucleotide excision repair (NER) is an essential DNA repair system distinguished from other such systems by its extraordinary versatility. NER removes a wide variety of structurally dissimilar lesions having only their bulkiness in common. NER can also repair several less bulky nucleobase lesions, such as 8-oxoguanine. Thus, how a single DNA repair system distinguishes such a diverse array of structurally divergent lesions from undamaged DNA has been one of the great unsolved mysteries in the field of genome maintenance. Here we employ a synthetic crystallography approach to obtain crystal structures of the pivotal NER enzyme UvrB in complex with duplex DNA, trapped at the stage of lesion-recognition. These structures coupled with biochemical studies suggest that UvrB integrates the ATPase-dependent helicase/translocase and lesion-recognition activities. Our work also conclusively establishes the identity of the lesion-containing strand and provides a compelling insight to how UvrB recognizes a diverse array of DNA lesions.
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Affiliation(s)
- Seung-Joo Lee
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Rou-Jia Sung
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Gregory L. Verdine
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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18
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Novel Sequence Features of DNA Repair Genes/Proteins from Deinococcus Species Implicated in Protection from Oxidatively Generated Damage. Genes (Basel) 2018. [PMID: 29518000 PMCID: PMC5867870 DOI: 10.3390/genes9030149] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Deinococcus species display a high degree of resistance to radiation and desiccation due to their ability to protect critical proteome from oxidatively generated damage; however, the underlying mechanisms are not understood. Comparative analysis of DNA repair proteins reported here has identified 22 conserved signature indels (CSIs) in the proteins UvrA1, UvrC, UvrD, UvsE, MutY, MutM, Nth, RecA, RecD, RecG, RecQ, RecR, RuvC, RadA, PolA, DnaE, LigA, GyrA and GyrB, that are uniquely shared by all/most Deinococcus homologs. Of these CSIs, a 30 amino acid surface-exposed insert in the Deinococcus UvrA1, which distinguishes it from all other UvrA homologs, is of much interest. The uvrA1 gene in Deinococcus also exhibits specific genetic linkage (predicted operonic arrangement) to genes for three other proteins including a novel Deinococcus-specific transmembrane protein (designated dCSP-1) and the proteins DsbA and DsbB, playing central roles in protein disulfide bond formation by oxidation-reduction of CXXC (C represents cysteine, X any other amino acid) motifs. The CXXC motifs provide important targets for oxidation damage and they are present in many DNA repair proteins including five in UvrA, which are part of Zinc-finger elements. A conserved insert specific for Deinococcus is also present in the DsbA protein. Additionally, the uvsE gene in Deinococcus also shows specific linkage to the gene for a membrane-associated protein. To account for these novel observations, a model is proposed where specific interaction of the Deinococcus UvrA1 protein with membrane-bound dCSP-1 enables the UvrA1 to receive electrons from DsbA-DsbB oxido-reductase machinery to ameliorate oxidation damage in the UvrA1 protein.
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19
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McMillan LJ, Hwang S, Farah RE, Koh J, Chen S, Maupin-Furlow JA. Multiplex quantitative SILAC for analysis of archaeal proteomes: a case study of oxidative stress responses. Environ Microbiol 2017; 20:385-401. [PMID: 29194950 DOI: 10.1111/1462-2920.14014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 01/08/2023]
Abstract
Stable isotope labelling of amino acids in cell culture (SILAC) is a quantitative proteomic method that can illuminate new pathways used by cells to adapt to different lifestyles and niches. Archaea, while thriving in extreme environments and accounting for ∼20%-40% of the Earth's biomass, have not been analyzed with the full potential of SILAC. Here, we report SILAC for quantitative comparison of archaeal proteomes, using Haloferax volcanii as a model. A double auxotroph was generated that allowed for complete incorporation of 13 C/15 N-lysine and 13 C-arginine such that each peptide derived from trypsin digestion was labelled. This strain was found amenable to multiplex SILAC by case study of responses to oxidative stress by hypochlorite. A total of 2565 proteins was identified by LC-MS/MS analysis (q-value ≤ 0.01) that accounted for 64% of the theoretical proteome. Of these, 176 proteins were altered at least 1.5-fold (p-value < 0.05) in abundance during hypochlorite stress. Many of the differential proteins were of unknown function. Those of known function included transcription factor homologs related to oxidative stress by 3D-homology modelling and orthologous group comparisons. Thus, SILAC is found to be an ideal method for quantitative proteomics of archaea that holds promise to unravel gene function.
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Affiliation(s)
- Lana J McMillan
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA.,Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Sungmin Hwang
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Rawan E Farah
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Jin Koh
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32611, USA
| | - Sixue Chen
- Genetics Institute, University of Florida, Gainesville, FL 32611, USA.,Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32611, USA.,Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Julie A Maupin-Furlow
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA.,Genetics Institute, University of Florida, Gainesville, FL 32611, USA
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20
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Van Houten B. A tale of two cities: A tribute to Aziz Sancar's Nobel Prize in Chemistry for his molecular characterization of NER. DNA Repair (Amst) 2016; 37:A3-A13. [PMID: 26861185 PMCID: PMC5068483 DOI: 10.1016/j.dnarep.2015.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Bennett Van Houten
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, United States.
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21
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Crystal structure of E. coli endonuclease V, an essential enzyme for deamination repair. Sci Rep 2015; 5:12754. [PMID: 26244280 PMCID: PMC4650699 DOI: 10.1038/srep12754] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/03/2015] [Indexed: 12/26/2022] Open
Abstract
Endonuclease V (EndoV) is a ubiquitous protein present in all three kingdoms of life, responsible for the specific cleavages at the second phosphodiester bond 3’ to inosine. E. coli EndoV (EcEndoV) is the first member discovered in the EndoV family. It is a small protein with a compact gene organization, yet with a wide spectrum of substrate specificities. However, the structural basis of its substrate recognition is not well understood. In this study, we determined the 2.4 Å crystal structure of EcEndoV. The enzyme preserves the general ‘RNase H-like motif’ structure. Two subunits are almost fully resolved in the asymmetric unit, but they are not related by any 2-fold axes. Rather, they establish “head-to-shoulder” contacts with loose interactions between each other. Mutational studies show that mutations that disrupt the association mode of the two subunits also decrease the cleavage efficiencies of the enzyme. Further biochemical studies suggest that EcEndoV is able to bind to single-stranded, undamaged DNA substrates without sequence specificity, and forms two types of complexes in a metal-independent manner, which may explain the wide spectrum of substrate specificities of EcEndoV.
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22
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Dalhus B, Alseth I, Bjørås M. Structural basis for incision at deaminated adenines in DNA and RNA by endonuclease V. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 117:134-142. [PMID: 25824682 DOI: 10.1016/j.pbiomolbio.2015.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 03/19/2015] [Accepted: 03/20/2015] [Indexed: 01/15/2023]
Abstract
Deamination of the exocyclic amines in adenine, guanine and cytosine forms base lesions that may lead to mutations if not removed by DNA repair proteins. Prokaryotic endonuclease V (EndoV/Nfi) has long been known to incise DNA 3' to a variety of base lesions, including deaminated adenine, guanine and cytosine. Biochemical and genetic data implicate that EndoV is involved in repair of these deaminated bases. In contrast to DNA glycosylases that remove a series of modified/damaged bases in DNA by direct excision of the nucleobase, EndoV cleaves the DNA sugar phosphate backbone at the second phosphodiester 3' to the lesion without removing the deaminated base. Structural investigation of this unusual incision by EndoV has unravelled an enzyme with separate base lesion and active site pockets. A novel wedge motif was identified as a DNA strand-separation feature important for damage detection. Human EndoV appears inactive on DNA, but has been shown to incise various RNA substrates containing inosine. Inosine is the deamination product of adenosine and is frequently found in RNA. The structural basis for discrimination between DNA and RNA by human EndoV remains elusive.
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Affiliation(s)
- Bjørn Dalhus
- Department of Medical Biochemistry, Institute for Clinical Medicine, University of Oslo, PO Box 4950, Nydalen, N-0424 Oslo, Norway; Department of Microbiology, Clinic for Diagnostics and Intervention, Oslo University Hospital, Rikshospitalet, PO Box 4950, Nydalen, N-0424 Oslo, Norway.
| | - Ingrun Alseth
- Department of Microbiology, Clinic for Diagnostics and Intervention, Oslo University Hospital, Rikshospitalet, PO Box 4950, Nydalen, N-0424 Oslo, Norway
| | - Magnar Bjørås
- Department of Microbiology, Clinic for Diagnostics and Intervention, Oslo University Hospital, Rikshospitalet, PO Box 4950, Nydalen, N-0424 Oslo, Norway
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23
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Alseth I, Dalhus B, Bjørås M. Inosine in DNA and RNA. Curr Opin Genet Dev 2014; 26:116-23. [PMID: 25173738 DOI: 10.1016/j.gde.2014.07.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 12/25/2022]
Abstract
Deamination of the nucleobases in DNA and RNA is a result of spontaneous hydrolysis, endogenous or environmental factors as well as deaminase enzymes. Adenosine is deaminated to inosine which is miscoding and preferentially base pairs with cytosine. In the case of DNA, this is a premutagenic event that is counteracted by DNA repair enzymes specifically engaged in recognition and removal of inosine. However, in RNA, inosine is an essential modification introduced by specialized enzymes in a highly regulated manner to generate transcriptome diversity. Defect editing is seen in various human disease including cancer, viral infections and neurological and psychiatric disorders. Enzymes catalyzing the deaminase reaction are well characterized and recently an unexpected function of Endonuclease V in RNA processing was revealed. Whereas bacterial Endonuclease V enzymes are classified as DNA repair enzymes, it appears that the mammalian enzymes are involved in processing of inosine in RNA. This yields an interesting yet unexplored, link between DNA and RNA processing. Further work is needed to gain understanding of the impact of inosine in DNA and RNA under normal physiology and disease progression.
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Affiliation(s)
- Ingrun Alseth
- Department of Microbiology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Bjørn Dalhus
- Department of Microbiology, University of Oslo and Oslo University Hospital, Oslo, Norway; Department of Medical Biochemistry, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Magnar Bjørås
- Department of Microbiology, University of Oslo and Oslo University Hospital, Oslo, Norway; Department of Medical Biochemistry, University of Oslo and Oslo University Hospital, Oslo, Norway.
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24
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Zhang Z, Hao Z, Wang Z, Li Q, Xie W. Structure of human endonuclease V as an inosine-specific ribonuclease. ACTA ACUST UNITED AC 2014; 70:2286-94. [PMID: 25195743 DOI: 10.1107/s139900471401356x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 06/11/2014] [Indexed: 11/10/2022]
Abstract
The 6-aminopurine ring of adenosine (A) can be deaminated to form the 6-oxopurine of inosine (I). Endonuclease Vs (EndoVs) are inosine-specific nucleases that cleave at the second phosphodiester bond 3' to inosine. EndoV proteins are highly conserved in all domains of life, but the bacterial and human enzymes seem to display distinct substrate preferences. While the bacterial enzymes exhibit high cleavage efficiency on various nucleic acid substrates, human EndoV (hEndoV) is most active towards ssRNA but is much less active towards other substrates. However, the structural basis of substrate recognition by hEndoV is not well understood. In this study, the 2.3 Å resolution crystal structure of hEndoV was determined and its unusual RNA-cleaving properties were investigated. The enzyme preserves the general `RNase H-like' structure, especially in the wedge motif, the metal-binding site and the hypoxanthine-binding pocket. hEndoV also features several extra insertions and a characteristic four-cysteine motif, in which Cys227 and Cys228, two cysteines that are highly conserved in higher eukaryotes, play important roles in catalysis. The structure presented here helps in understanding the substrate preference of hEndoV catalysis.
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Affiliation(s)
- Zhemin Zhang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou 510275, People's Republic of China
| | - Zhitai Hao
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou 510275, People's Republic of China
| | - Zhong Wang
- Centre for Cellular and Structural Biology, The Sun Yat-Sen University, 132 East Circle Road, University City, Guangzhou 510006, People's Republic of China
| | - Qing Li
- Centre for Cellular and Structural Biology, The Sun Yat-Sen University, 132 East Circle Road, University City, Guangzhou 510006, People's Republic of China
| | - Wei Xie
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou 510275, People's Republic of China
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25
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Van Houten B, Kad N. Investigation of bacterial nucleotide excision repair using single-molecule techniques. DNA Repair (Amst) 2014; 20:41-48. [PMID: 24472181 PMCID: PMC5053424 DOI: 10.1016/j.dnarep.2013.10.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 10/31/2013] [Indexed: 12/23/2022]
Abstract
Despite three decades of biochemical and structural analysis of the prokaryotic nucleotide excision repair (NER) system, many intriguing questions remain with regard to how the UvrA, UvrB, and UvrC proteins detect, verify and remove a wide range of DNA lesions. Single-molecule techniques have begun to allow more detailed understanding of the kinetics and action mechanism of this complex process. This article reviews how atomic force microscopy and fluorescence microscopy have captured new glimpses of how these proteins work together to mediate NER.
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Affiliation(s)
- Bennett Van Houten
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Neil Kad
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
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26
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Hughes CD, Wang H, Ghodke H, Simons M, Towheed A, Peng Y, Van Houten B, Kad NM. Real-time single-molecule imaging reveals a direct interaction between UvrC and UvrB on DNA tightropes. Nucleic Acids Res 2013; 41:4901-12. [PMID: 23511970 PMCID: PMC3643590 DOI: 10.1093/nar/gkt177] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Nucleotide excision DNA repair is mechanistically conserved across all kingdoms of life. In prokaryotes, this multi-enzyme process requires six proteins: UvrA–D, DNA polymerase I and DNA ligase. To examine how UvrC locates the UvrB–DNA pre-incision complex at a site of damage, we have labeled UvrB and UvrC with different colored quantum dots and quantitatively observed their interactions with DNA tightropes under a variety of solution conditions using oblique angle fluorescence imaging. Alone, UvrC predominantly interacts statically with DNA at low salt. Surprisingly, however, UvrC and UvrB together in solution bind to form the previously unseen UvrBC complex on duplex DNA. This UvrBC complex is highly motile and engages in unbiased one-dimensional diffusion. To test whether UvrB makes direct contact with the DNA in the UvrBC–DNA complex, we investigated three UvrB mutants: Y96A, a β-hairpin deletion and D338N. These mutants affected the motile properties of the UvrBC complex, indicating that UvrB is in intimate contact with the DNA when bound to UvrC. Given the in vivo excess of UvrB and the abundance of UvrBC in our experiments, this newly identified complex is likely to be the predominant form of UvrC in the cell.
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Affiliation(s)
- Craig D Hughes
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
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27
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Abstract
Nucleotide excision repair (NER) has allowed bacteria to flourish in many different niches around the globe that inflict harsh environmental damage to their genetic material. NER is remarkable because of its diverse substrate repertoire, which differs greatly in chemical composition and structure. Recent advances in structural biology and single-molecule studies have given great insight into the structure and function of NER components. This ensemble of proteins orchestrates faithful removal of toxic DNA lesions through a multistep process. The damaged nucleotide is recognized by dynamic probing of the DNA structure that is then verified and marked for dual incisions followed by excision of the damage and surrounding nucleotides. The opposite DNA strand serves as a template for repair, which is completed after resynthesis and ligation.
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Affiliation(s)
- Caroline Kisker
- Rudolf-Virchow-Center for Experimental Biomedicine, University of Wuerzburg, 97080 Wuerzburg, Germany.
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28
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Couvé S, Ishchenko AA, Fedorova OS, Ramanculov EM, Laval J, Saparbaev M. Direct DNA Lesion Reversal and Excision Repair in Escherichia coli. EcoSal Plus 2013; 5. [PMID: 26442931 DOI: 10.1128/ecosalplus.7.2.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Indexed: 06/05/2023]
Abstract
Cellular DNA is constantly challenged by various endogenous and exogenous genotoxic factors that inevitably lead to DNA damage: structural and chemical modifications of primary DNA sequence. These DNA lesions are either cytotoxic, because they block DNA replication and transcription, or mutagenic due to the miscoding nature of the DNA modifications, or both, and are believed to contribute to cell lethality and mutagenesis. Studies on DNA repair in Escherichia coli spearheaded formulation of principal strategies to counteract DNA damage and mutagenesis, such as: direct lesion reversal, DNA excision repair, mismatch and recombinational repair and genotoxic stress signalling pathways. These DNA repair pathways are universal among cellular organisms. Mechanistic principles used for each repair strategies are fundamentally different. Direct lesion reversal removes DNA damage without need for excision and de novo DNA synthesis, whereas DNA excision repair that includes pathways such as base excision, nucleotide excision, alternative excision and mismatch repair, proceeds through phosphodiester bond breakage, de novo DNA synthesis and ligation. Cell signalling systems, such as adaptive and oxidative stress responses, although not DNA repair pathways per se, are nevertheless essential to counteract DNA damage and mutagenesis. The present review focuses on the nature of DNA damage, direct lesion reversal, DNA excision repair pathways and adaptive and oxidative stress responses in E. coli.
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29
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Dynamics of lesion processing by bacterial nucleotide excision repair proteins. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:1-24. [PMID: 22749140 DOI: 10.1016/b978-0-12-387665-2.00001-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Single-molecule approaches permit an unrivalled view of how complex systems operate and have recently been used to understand DNA-protein interactions. These tools have enabled advances in a particularly challenging problem, the search for damaged sites on DNA. DNA repair proteins are present at the level of just a few hundred copies in bacterial cells to just a few thousand in human cells, and they scan the entire genome in search of their specific substrates. How do these proteins achieve this herculean task when their targets may differ from undamaged DNA by only a single hydrogen bond? Here we examine, using single-molecule approaches, how the prokaryotic nucleotide excision repair system balances the necessity for speed against specificity. We discuss issues at a theoretical, biological, and technical level and finally pose questions for future research.
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30
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Kleinstiver BP, Bérubé-Janzen W, Fernandes AD, Edgell DR. Divalent metal ion differentially regulates the sequential nicking reactions of the GIY-YIG homing endonuclease I-BmoI. PLoS One 2011; 6:e23804. [PMID: 21887323 PMCID: PMC3161791 DOI: 10.1371/journal.pone.0023804] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 07/26/2011] [Indexed: 01/30/2023] Open
Abstract
Homing endonucleases are site-specific DNA endonucleases that function as mobile genetic elements by introducing double-strand breaks or nicks at defined locations. Of the major families of homing endonucleases, the modular GIY-YIG endonucleases are least understood in terms of mechanism. The GIY-YIG homing endonuclease I-BmoI generates a double-strand break by sequential nicking reactions during which the single active site of the GIY-YIG nuclease domain must undergo a substantial reorganization. Here, we show that divalent metal ion plays a significant role in regulating the two independent nicking reactions by I-BmoI. Rate constant determination for each nicking reaction revealed that limiting divalent metal ion has a greater impact on the second strand than the first strand nicking reaction. We also show that substrate mutations within the I-BmoI cleavage site can modulate the first strand nicking reaction over a 314-fold range. Additionally, in-gel DNA footprinting with mutant substrates and modeling of an I-BmoI-substrate complex suggest that amino acid contacts to a critical GC-2 base pair are required to induce a bottom-strand distortion that likely directs conformational changes for reaction progress. Collectively, our data implies mechanistic roles for divalent metal ion and substrate bases, suggesting that divalent metal ion facilitates the re-positioning of the GIY-YIG nuclease domain between sequential nicking reactions.
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Affiliation(s)
- Benjamin P. Kleinstiver
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Wesley Bérubé-Janzen
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Andrew D. Fernandes
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
- Department of Applied Mathematics, The University of Western Ontario, London, Ontario, Canada
| | - David R. Edgell
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
- * E-mail:
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31
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Liu Y, Reeves D, Kropachev K, Cai Y, Ding S, Kolbanovskiy M, Kolbanovskiy A, Bolton JL, Broyde S, Van Houten B, Geacintov NE. Probing for DNA damage with β-hairpins: similarities in incision efficiencies of bulky DNA adducts by prokaryotic and human nucleotide excision repair systems in vitro. DNA Repair (Amst) 2011; 10:684-96. [PMID: 21741328 DOI: 10.1016/j.dnarep.2011.04.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nucleotide excision repair (NER) is an important prokaryotic and eukaryotic defense mechanism that removes a large variety of structurally distinct lesions in cellular DNA. While the proteins involved are completely different, the mode of action of these two repair systems is similar, involving a cut-and-patch mechanism in which an oligonucleotide sequence containing the lesion is excised. The prokaryotic and eukaryotic NER damage-recognition factors have common structural features of β-hairpin intrusion between the two DNA strands at the site of the lesion. In the present study, we explored the hypothesis that this common β-hairpin intrusion motif is mirrored in parallel NER incision efficiencies in the two systems. We have utilized human HeLa cell extracts and the prokaryotic UvrABC proteins to determine their relative NER incision efficiencies. We report here comparisons of relative NER efficiencies with a set of stereoisomeric DNA lesions derived from metabolites of benzo[a]pyrene and equine estrogens in different sequence contexts, utilizing 21 samples. We found a general qualitative trend toward similar relative NER incision efficiencies for ∼65% of these substrates; the other cases deviate mostly by ∼30% or less from a perfect correlation, although several more distant outliers are also evident. This resemblance is consistent with the hypothesis that lesion recognition through β-hairpin insertion, a common feature of the two systems, is facilitated by local thermodynamic destabilization induced by the lesions in both cases. In the case of the UvrABC system, varying the nature of the UvrC endonuclease, while maintaining the same UvrA/B proteins, can markedly affect the relative incision efficiencies. These observations suggest that, in addition to recognition involving the initial modified duplexes, downstream events involving UvrC can also play a role in distinguishing and processing different lesions in prokaryotic NER.
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Affiliation(s)
- Yang Liu
- Chemistry Department, New York University, New York, NY 10003, USA
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32
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Fuss JO, Tainer JA. XPB and XPD helicases in TFIIH orchestrate DNA duplex opening and damage verification to coordinate repair with transcription and cell cycle via CAK kinase. DNA Repair (Amst) 2011; 10:697-713. [PMID: 21571596 DOI: 10.1016/j.dnarep.2011.04.028] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Helicases must unwind DNA at the right place and time to maintain genomic integrity or gene expression. Biologically critical XPB and XPD helicases are key members of the human TFIIH complex; they anchor CAK kinase (cyclinH, MAT1, CDK7) to TFIIH and open DNA for transcription and for repair of duplex distorting damage by nucleotide excision repair (NER). NER is initiated by arrested RNA polymerase or damage recognition by XPC-RAD23B with or without DDB1/DDB2. XP helicases, named for their role in the extreme sun-mediated skin cancer predisposition xeroderma pigmentosum (XP), are then recruited to asymmetrically unwind dsDNA flanking the damage. XPB and XPD genetic defects can also cause premature aging with profound neurological defects without increased cancers: Cockayne syndrome (CS) and trichothiodystrophy (TTD). XP helicase patient phenotypes cannot be predicted from the mutation position along the linear gene sequence and adjacent mutations can cause different diseases. Here we consider the structural biology of DNA damage recognition by XPC-RAD23B, DDB1/DDB2, RNAPII, and ATL, and of helix unwinding by the XPB and XPD helicases plus the bacterial repair helicases UvrB and UvrD in complex with DNA. We then propose unified models for TFIIH assembly and roles in NER. Collective crystal structures with NMR and electron microscopy results reveal functional motifs, domains, and architectural elements that contribute to biological activities: damaged DNA binding, translocation, unwinding, and ATP driven changes plus TFIIH assembly and signaling. Coupled with mapping of patient mutations, these combined structural analyses provide a framework for integrating and unifying the rich biochemical and cellular information that has accumulated over forty years of study. This integration resolves puzzles regarding XP helicase functions and suggests that XP helicase positions and activities within TFIIH detect and verify damage, select the damaged strand for incision, and coordinate repair with transcription and cell cycle through CAK signaling.
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Affiliation(s)
- Jill O Fuss
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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33
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Jaciuk M, Nowak E, Skowronek K, Tańska A, Nowotny M. Structure of UvrA nucleotide excision repair protein in complex with modified DNA. Nat Struct Mol Biol 2011; 18:191-7. [PMID: 21240268 PMCID: PMC3428727 DOI: 10.1038/nsmb.1973] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 11/09/2010] [Indexed: 12/31/2022]
Abstract
One of the primary pathways for removal of DNA damage is nucleotide excision repair (NER). In bacteria, the UvrA protein is the component of NER that locates the lesion. A notable feature of NER is its ability to act on many DNA modifications that vary in chemical structure. So far, the mechanism underlying this broad specificity has been unclear. Here, we report the first crystal structure of a UvrA protein in complex with a chemically modified oligonucleotide. The structure shows that the UvrA dimer does not contact the site of lesion directly, but rather binds the DNA regions on both sides of the modification. The DNA region harboring the modification is deformed, with the double helix bent and unwound. UvrA uses damage-induced deformations of the DNA and a less rigid structure of the modified double helix for indirect readout of the lesion.
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Affiliation(s)
- Marcin Jaciuk
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Elżbieta Nowak
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Krzysztof Skowronek
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland. Correspondence should be addressed to M.N. ()
| | - Anna Tańska
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
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Morita R, Nakane S, Shimada A, Inoue M, Iino H, Wakamatsu T, Fukui K, Nakagawa N, Masui R, Kuramitsu S. Molecular mechanisms of the whole DNA repair system: a comparison of bacterial and eukaryotic systems. J Nucleic Acids 2010; 2010:179594. [PMID: 20981145 PMCID: PMC2957137 DOI: 10.4061/2010/179594] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 07/27/2010] [Indexed: 11/20/2022] Open
Abstract
DNA is subjected to many endogenous and exogenous damages. All organisms have developed a complex network of DNA repair mechanisms. A variety of different DNA repair pathways have been reported: direct reversal, base excision repair, nucleotide excision repair, mismatch repair, and recombination repair pathways. Recent studies of the fundamental mechanisms for DNA repair processes have revealed a complexity beyond that initially expected, with inter- and intrapathway complementation as well as functional interactions between proteins involved in repair pathways. In this paper we give a broad overview of the whole DNA repair system and focus on the molecular basis of the repair machineries, particularly in Thermus thermophilus HB8.
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Affiliation(s)
- Rihito Morita
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan
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35
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Sokolowska M, Czapinska H, Bochtler M. Hpy188I-DNA pre- and post-cleavage complexes--snapshots of the GIY-YIG nuclease mediated catalysis. Nucleic Acids Res 2010; 39:1554-64. [PMID: 20935048 PMCID: PMC3045582 DOI: 10.1093/nar/gkq821] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The GIY-YIG nuclease domain is present in all kingdoms of life and has diverse functions. It is found in the eukaryotic flap endonuclease and Holliday junction resolvase Slx1–Slx4, the prokaryotic nucleotide excision repair proteins UvrC and Cho, and in proteins of ‘selfish’ genetic elements. Here we present the structures of the ternary pre- and post-cleavage complexes of the type II GIY-YIG restriction endonuclease Hpy188I with DNA and a surrogate or catalytic metal ion, respectively. Our structures suggest that GIY-YIG nucleases catalyze DNA hydrolysis by a single substitution reaction. They are consistent with a previous proposal that a tyrosine residue (which we expect to occur in its phenolate form) acts as a general base for the attacking water molecule. In contrast to the earlier proposal, our data identify the general base with the GIY and not the YIG tyrosine. A conserved glutamate residue (Glu149 provided in trans in Hpy188I) anchors a single metal cation in the active site. This metal ion contacts the phosphate proS oxygen atom and the leaving group 3′-oxygen atom, presumably to facilitate its departure. Taken together, our data reveal striking analogy in the absence of homology between GIY-YIG and ββα-Me nucleases.
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Affiliation(s)
- Monika Sokolowska
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
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36
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Abstract
Nucleases cleave the phosphodiester bonds of nucleic acids and may be endo or exo, DNase or RNase, topoisomerases, recombinases, ribozymes, or RNA splicing enzymes. In this review, I survey nuclease activities with known structures and catalytic machinery and classify them by reaction mechanism and metal-ion dependence and by their biological function ranging from DNA replication, recombination, repair, RNA maturation, processing, interference, to defense, nutrient regeneration or cell death. Several general principles emerge from this analysis. There is little correlation between catalytic mechanism and biological function. A single catalytic mechanism can be adapted in a variety of reactions and biological pathways. Conversely, a single biological process can often be accomplished by multiple tertiary and quaternary folds and by more than one catalytic mechanism. Two-metal-ion-dependent nucleases comprise the largest number of different tertiary folds and mediate the most diverse set of biological functions. Metal-ion-dependent cleavage is exclusively associated with exonucleases producing mononucleotides and endonucleases that cleave double- or single-stranded substrates in helical and base-stacked conformations. All metal-ion-independent RNases generate 2',3'-cyclic phosphate products, and all metal-ion-independent DNases form phospho-protein intermediates. I also find several previously unnoted relationships between different nucleases and shared catalytic configurations.
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37
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Folding, DNA recognition, and function of GIY-YIG endonucleases: crystal structures of R.Eco29kI. Structure 2010; 18:1321-31. [PMID: 20800503 DOI: 10.1016/j.str.2010.07.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 06/28/2010] [Accepted: 07/01/2010] [Indexed: 11/21/2022]
Abstract
The GIY-YIG endonuclease family comprises hundreds of diverse proteins and a multitude of functions; none have been visualized bound to DNA. The structure of the GIY-YIG restriction endonuclease R.Eco29kI has been solved both alone and bound to its target site. The protein displays a domain-swapped homodimeric structure with several extended surface loops encircling the DNA. Only three side chains from each protein subunit contact DNA bases, two directly and one via a bridging solvent molecule. Both tyrosine residues within the GIY-YIG motif are positioned in the catalytic center near a putative nucleophilic water; the remainder of the active site resembles the HNH endonuclease family. The structure illustrates how the GIY-YIG scaffold has been adapted for the highly specific recognition of a DNA restriction site, in contrast to nonspecific DNA cleavage by GIY-YIG domains in homing endonucleases or structure-specific cleavage by DNA repair enzymes such as UvrC.
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38
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Alkyltransferase-like proteins: molecular switches between DNA repair pathways. Cell Mol Life Sci 2010; 67:3749-62. [PMID: 20502938 DOI: 10.1007/s00018-010-0405-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 05/04/2010] [Accepted: 05/10/2010] [Indexed: 01/08/2023]
Abstract
Alkyltransferase-like proteins (ATLs) play a role in the protection of cells from the biological effects of DNA alkylation damage. Although ATLs share functional motifs with the DNA repair protein and cancer chemotherapy target O⁶-alkylguanine-DNA alkyltransferase, they lack the reactive cysteine residue required for alkyltransferase activity, so its mechanism for cell protection was previously unknown. Here we review recent advances in unraveling the enigmatic cellular protection provided by ATLs against the deleterious effects of DNA alkylation damage. We discuss exciting new evidence that ATLs aid in the repair of DNA O⁶-alkylguanine lesions through a novel repair cross-talk between DNA-alkylation base damage responses and the DNA nucleotide excision repair pathway.
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39
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Kad NM, Wang H, Kennedy GG, Warshaw DM, Van Houten B. Collaborative dynamic DNA scanning by nucleotide excision repair proteins investigated by single- molecule imaging of quantum-dot-labeled proteins. Mol Cell 2010; 37:702-13. [PMID: 20227373 DOI: 10.1016/j.molcel.2010.02.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 10/14/2009] [Accepted: 12/23/2009] [Indexed: 11/29/2022]
Abstract
How DNA repair proteins sort through a genome for damage is one of the fundamental unanswered questions in this field. To address this problem, we uniquely labeled bacterial UvrA and UvrB with differently colored quantum dots and visualized how they interacted with DNA individually or together using oblique-angle fluorescence microscopy. UvrA was observed to utilize a three-dimensional search mechanism, binding transiently to the DNA for short periods (7 s). UvrA also was observed jumping from one DNA molecule to another over approximately 1 microm distances. Two UvrBs can bind to a UvrA dimer and collapse the search dimensionality of UvrA from three to one dimension by inducing a substantial number of UvrAB complexes to slide along the DNA. Three types of sliding motion were characterized: random diffusion, paused motion, and directed motion. This UvrB-induced change in mode of searching permits more rapid and efficient scanning of the genome for damage.
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Affiliation(s)
- Neil M Kad
- Department of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, UK.
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40
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Jia L, Kropachev K, Ding S, Van Houten B, Geacintov NE, Broyde S. Exploring damage recognition models in prokaryotic nucleotide excision repair with a benzo[a]pyrene-derived lesion in UvrB. Biochemistry 2009; 48:8948-57. [PMID: 19681599 DOI: 10.1021/bi9010072] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The UvrB protein is a central unit for damage recognition in the prokaryotic nucleotide excision repair system, which excises bulky DNA lesions. We have utilized molecular modeling and MD simulations based on crystal structures, mutagenesis, and fluorescence data, to model the 10R-(+)-cis-anti-B[a]P-N2-dG lesion, derived from the tumorigenic (+)-anti-B[a]PDE metabolite of benzo[a]pyrene, at different locations on the inner and outer strand in UvrB. Our results suggest that this lesion is accommodated on the inner strand where it might translocate through the tunnel created by the beta-hairpin and UvrB domain 1B and ultimately could be housed in the pocket behind the beta-hairpin prior to excision by UvrC. Lesions that vary in size and shape may be stopped at the gate to the tunnel, within the tunnel, or in the pocket when UvrC initiates excision. Common features of beta-hairpin intrusion between the two DNA strands and nucleotide flipping manifested in structures of prokaryotic and eukaryotic NER lesion recognition proteins are consistent with common recognition mechanisms, based on lesion-induced local thermodynamic distortion/destabilization and nucleotide flipping.
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Affiliation(s)
- Lei Jia
- Department of Biology, New York University, 100 Washington Square East, Room 1009, New York, New York 10003, USA
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41
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Roth HM, Tessmer I, Van Houten B, Kisker C. Bax1 is a novel endonuclease: implications for archaeal nucleotide excision repair. J Biol Chem 2009; 284:32272-8. [PMID: 19759013 DOI: 10.1074/jbc.m109.055913] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The helicases XPB and XPD are part of the TFIIH complex, which mediates transcription initiation as well as eukaryotic nucleotide excision repair (NER). Although there is no TFIIH complex present in archaea, most species contain both XPB and XPD and serve as a model for their eukaryotic homologs. Recently, a novel binding partner for XPB, Bax1 (binds archeal XPB), was identified in archaea. To gain insights into its role in NER, Bax1 from Thermoplasma acidophilum was characterized. We identified Bax1 as a novel Mg(2+)-dependent structure-specific endonuclease recognizing DNA containing a 3' overhang. Incision assays conducted with DNA substrates providing different lengths of the 3' overhang indicate that Bax1 specifically incises DNA in the single-stranded region of the 3' overhang 4-6 nucleotides to the single-stranded DNA/double-stranded DNA junction and thus is a structure-specific and not a sequence-specific endonuclease. In contrast, no incision was detected in the presence of a 5' overhang, double-stranded DNA, or DNA containing few unpaired nucleotides forming a bubble. Several Bax1 variants were generated based on multiple sequence alignments and examined with respect to their ability to perform the incision reaction. Residues Glu-124, Asp-132, Tyr-152, and Glu-155 show a dramatic reduction in incision activity, indicating a pivotal role in catalysis. Interestingly, Bax1 does not exhibit any incision activity in the presence of XPB, thus suggesting a role in NER in which the endonuclease activity is tightly regulated until the damage has been recognized and verified prior to the incision event.
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Affiliation(s)
- Heide M Roth
- Rudolf-Virchow-Center for Experimental Biomedicine, 97080 Würzburg, Germany
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42
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Structures of endonuclease V with DNA reveal initiation of deaminated adenine repair. Nat Struct Mol Biol 2009; 16:138-43. [PMID: 19136958 PMCID: PMC3560532 DOI: 10.1038/nsmb.1538] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 11/21/2008] [Indexed: 01/07/2023]
Abstract
Endonuclease V (EndoV) initiates a major base-repair pathway for nitrosative deamination resulting from endogenous processes and increased by oxidative stress from mitochondrial dysfunction or inflammatory responses. We solved the crystal structures of Thermotoga maritima EndoV in complex with a hypoxanthine lesion substrate and with product DNA. The PYIP wedge motif acts as a minor groove-damage sensor for helical distortions and base mismatches and separates DNA strands at the lesion. EndoV incises DNA with an unusual offset nick 1 nucleotide 3' of the lesion, as the deaminated adenine is rotated approximately 90 degrees into a recognition pocket approximately 8 A from the catalytic site. Tight binding by the lesion-recognition pocket in addition to Mg(2+) and hydrogen-bonding interactions to the DNA ends stabilize the product complex, suggesting an orderly recruitment of downstream proteins in this base-repair pathway.
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43
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Nowotny M. Retroviral integrase superfamily: the structural perspective. EMBO Rep 2009; 10:144-51. [PMID: 19165139 DOI: 10.1038/embor.2008.256] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Accepted: 12/15/2008] [Indexed: 11/09/2022] Open
Abstract
The retroviral integrase superfamily (RISF) comprises numerous important nucleic acid-processing enzymes, including transposases, integrases and various nucleases. These enzymes are involved in a wide range of processes such as transposition, replication and repair of DNA, homologous recombination, and RNA-mediated gene silencing. Two out of the four enzymes that are encoded by the human immunodeficiency virus--RNase H1 and integrase--are members of this superfamily. RISF enzymes act on various substrates, and yet show remarkable mechanistic and structural similarities. All share a common fold of the catalytic core and the active site, which is composed primarily of carboxylate residues. Here, I present RISF proteins from a structural perspective, describing the individual members and the common and divergent elements of their structures, as well as the mechanistic insights gained from the structures of RNase H1 enzyme complexes with RNA/DNA hybrids.
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Affiliation(s)
- Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, 02-109, Warsaw, Poland.
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44
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Majorek KA, Bujnicki JM. Modeling of Escherichia coli Endonuclease V structure in complex with DNA. J Mol Model 2008; 15:173-82. [PMID: 19043748 DOI: 10.1007/s00894-008-0414-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Accepted: 10/02/2008] [Indexed: 01/24/2023]
Abstract
Endonuclease V (EndoV) is a metal-dependent DNA repair enzyme involved in removal of deaminated bases (e.g., deoxyuridine, deoxyinosine, and deoxyxanthosine), with pairing specificities different from the original bases. Homologs of EndoV are present in all major phyla from bacteria to humans and their function is quite well analyzed. EndoV has been combined with DNA ligase to develop an enzymatic method for mutation scanning and has been engineered to obtain variants with different substrate specificities that serve as improved tools in mutation recognition and cancer mutation scanning. However, little is known about the structure and mechanism of substrate DNA binding by EndoV. Here, we present the results of a bioinformatic analysis and a structural model of EndoV from Escherichia coli in complex with DNA. The structure was obtained by a combination of fold-recognition, comparative modeling, de novo modeling and docking methods. The modeled structure provides a convenient tool to study protein sequence-structure-function relationships in EndoV and to engineer its further variants.
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Affiliation(s)
- Karolina A Majorek
- Institute for Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland
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45
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Croteau DL, Peng Y, Van Houten B. DNA repair gets physical: mapping an XPA-binding site on ERCC1. DNA Repair (Amst) 2008; 7:819-26. [PMID: 18343204 DOI: 10.1016/j.dnarep.2008.01.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 01/23/2008] [Accepted: 01/24/2008] [Indexed: 11/27/2022]
Abstract
Two recent reports provide new physical information on how the XPA protein recruits the ERCC1-XPF heterodimer to the site of damage during the process of mammalian nucleotide excision repair (NER). Using chemical shift perturbation NMR experiments, the contact sites between a central fragment of ERCC1 and an XPA fragment have been mapped. While both studies agree with regard to the XPA-binding site, they differ on whether the ERCC1-XPA complex can simultaneously bind DNA. These studies have important implications for both the molecular process and the design of potential inhibitors of NER.
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Affiliation(s)
- Deborah L Croteau
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, United States
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46
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Goosen N, Moolenaar GF. Repair of UV damage in bacteria. DNA Repair (Amst) 2008; 7:353-79. [DOI: 10.1016/j.dnarep.2007.09.002] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Accepted: 09/06/2007] [Indexed: 10/22/2022]
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47
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Croteau DL, DellaVecchia MJ, Perera L, Van Houten B. Cooperative damage recognition by UvrA and UvrB: identification of UvrA residues that mediate DNA binding. DNA Repair (Amst) 2008; 7:392-404. [PMID: 18248777 DOI: 10.1016/j.dnarep.2007.11.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 11/07/2007] [Accepted: 11/12/2007] [Indexed: 11/24/2022]
Abstract
Nucleotide excision repair (NER) is responsible for the recognition and removal of numerous structurally unrelated DNA lesions. In prokaryotes, the proteins UvrA, UvrB and UvrC orchestrate the recognition and excision of aberrant lesions from DNA. Despite the progress we have made in understanding the NER pathway, it remains unclear how the UvrA dimer interacts with DNA to facilitate DNA damage recognition. The purpose of this study was to define amino acid residues in UvrA that provide binding energy to DNA. Based on conservation among approximately 300 UvrA sequences and 3D-modeling, two positively charged residues, Lys680 and Arg691, were predicted to be important for DNA binding. Mutagenesis and biochemical analysis of Bacillus caldontenax UvrA variant proteins containing site directed mutations at these residues demonstrate that Lys680 and Arg691 make a significant contribution toward the DNA binding affinity of UvrA. Replacing these side chains with alanine or negatively charged residues decreased UvrA binding 3-37-fold. Survival studies indicated that these mutant proteins complemented a WP2 uvrA(-) strain of bacteria 10-100% of WT UvrA levels. Further analysis by DNase I footprinting of the double UvrA mutant revealed that the UvrA DNA binding defects caused a slower rate of transfer of DNA to UvrB. Consequently, the mutants initiated the oligonucleotide incision assay nearly as well as WT UvrA thus explaining the observed mild phenotype in the survival assay. Based on our findings we propose a model of how UvrA binds to DNA.
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Affiliation(s)
- Deborah L Croteau
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Pakotiprapha D, Inuzuka Y, Bowman BR, Moolenaar GF, Goosen N, Jeruzalmi D, Verdine GL. Crystal structure of Bacillus stearothermophilus UvrA provides insight into ATP-modulated dimerization, UvrB interaction, and DNA binding. Mol Cell 2007; 29:122-33. [PMID: 18158267 DOI: 10.1016/j.molcel.2007.10.026] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 09/05/2007] [Accepted: 10/10/2007] [Indexed: 10/22/2022]
Abstract
The nucleotide excision repair pathway corrects many structurally unrelated DNA lesions. Damage recognition in bacteria is performed by UvrA, a member of the ABC ATPase superfamily whose functional form is a dimer with four nucleotide-binding domains (NBDs), two per protomer. In the 3.2 A structure of UvrA from Bacillus stearothermophilus, we observe that the nucleotide-binding sites are formed in an intramolecular fashion and are not at the dimer interface as is typically found in other ABC ATPases. UvrA also harbors two unique domains; we show that one of these is required for interaction with UvrB, its partner in lesion recognition. In addition, UvrA contains three zinc modules, the number and ligand sphere of which differ from previously published models. Structural analysis, biochemical experiments, surface electrostatics, and sequence conservation form the basis for models of ATP-modulated dimerization, UvrA-UvrB interaction, and DNA binding during the search for lesions.
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Affiliation(s)
- Danaya Pakotiprapha
- Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA
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