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Matsuda R, Suzuki S, Kurosawa N. Genetic Study of Four Candidate Holliday Junction Processing Proteins in the Thermophilic Crenarchaeon Sulfolobus acidocaldarius. Int J Mol Sci 2022; 23:ijms23020707. [PMID: 35054893 PMCID: PMC8775617 DOI: 10.3390/ijms23020707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/24/2021] [Accepted: 01/06/2022] [Indexed: 02/01/2023] Open
Abstract
Homologous recombination (HR) is thought to be important for the repair of stalled replication forks in hyperthermophilic archaea. Previous biochemical studies identified two branch migration helicases (Hjm and PINA) and two Holliday junction (HJ) resolvases (Hjc and Hje) as HJ-processing proteins; however, due to the lack of genetic evidence, it is still unclear whether these proteins are actually involved in HR in vivo and how their functional relation is associated with the process. To address the above questions, we constructed hjc-, hje-, hjm-, and pina single-knockout strains and double-knockout strains of the thermophilic crenarchaeon Sulfolobus acidocaldarius and characterized the mutant phenotypes. Notably, we succeeded in isolating the hjm- and/or pina-deleted strains, suggesting that the functions of Hjm and PINA are not essential for cellular growth in this archaeon, as they were previously thought to be essential. Growth retardation in Δpina was observed at low temperatures (cold sensitivity). When deletion of the HJ resolvase genes was combined, Δpina Δhjc and Δpina Δhje exhibited severe cold sensitivity. Δhjm exhibited severe sensitivity to interstrand crosslinkers, suggesting that Hjm is involved in repairing stalled replication forks, as previously demonstrated in euryarchaea. Our findings suggest that the function of PINA and HJ resolvases is functionally related at lower temperatures to support robust cellular growth, and Hjm is important for the repair of stalled replication forks in vivo.
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Pérez-Arnaiz P, Dattani A, Smith V, Allers T. Haloferax volcanii-a model archaeon for studying DNA replication and repair. Open Biol 2020; 10:200293. [PMID: 33259746 PMCID: PMC7776575 DOI: 10.1098/rsob.200293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022] Open
Abstract
The tree of life shows the relationship between all organisms based on their common ancestry. Until 1977, it comprised two major branches: prokaryotes and eukaryotes. Work by Carl Woese and other microbiologists led to the recategorization of prokaryotes and the proposal of three primary domains: Eukarya, Bacteria and Archaea. Microbiological, genetic and biochemical techniques were then needed to study the third domain of life. Haloferax volcanii, a halophilic species belonging to the phylum Euryarchaeota, has provided many useful tools to study Archaea, including easy culturing methods, genetic manipulation and phenotypic screening. This review will focus on DNA replication and DNA repair pathways in H. volcanii, how this work has advanced our knowledge of archaeal cellular biology, and how it may deepen our understanding of bacterial and eukaryotic processes.
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Affiliation(s)
| | | | | | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
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3
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Ahmad S, Huang Q, Ni J, Xiao Y, Yang Y, Shen Y. Functional Analysis of the NucS/EndoMS of the Hyperthermophilic Archaeon Sulfolobus islandicus REY15A. Front Microbiol 2020; 11:607431. [PMID: 33335523 PMCID: PMC7736090 DOI: 10.3389/fmicb.2020.607431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/10/2020] [Indexed: 11/13/2022] Open
Abstract
EndoMS is a recently identified mismatch specific endonuclease in Thermococcales of Archaea and Mycobacteria of Bacteria. The homologs of EndoMS are conserved in Archaea and Actinobacteria, where classic MutS-MutL-mediated DNA mismatch repair pathway is absent or non-functional. Here, we report a study on the in vitro mismatch cleavage activity and in vivo function of an EndoMS homolog (SisEndoMS) from Sulfolobus islandicus REY15A, the model archaeon belonging to Crenarchaeota. SisEndoMS is highly active on duplex DNA containing G/T, G/G, and T/T mismatches. Interestingly, the cleavage activity of SisEndoMS is stimulated by the heterotrimeric PCNAs, and when Mn2+ was used as the co-factor instead of Mg2+, SisEndoMS was also active on DNA substrates containing C/T or A/G mismatches, suggesting that the endonuclease activity can be regulated by ion co-factors and accessory proteins. We compared the spontaneous mutation rate of the wild type strain REY15A and ∆endoMS by counter selection against 5-fluoroorotic acid (5-FOA). The endoMS knockout mutant had much higher spontaneous mutation rate (5.06 × 10−3) than that of the wild type (4.6 × 10−6). A mutation accumulation analysis also showed that the deletion mutant had a higher mutation occurrence than the wild type, with transition mutation being the dominant, suggesting that SisEndoMS is responsible for mutation avoidance in this hyperthermophilic archaeon. Overexpression of the wild type SisEndoMS in S. islandicus resulted in retarded growth and abnormal cell morphology, similar to strains overexpressing Hje and Hjc, the Holliday junction endonucleases. Transcriptomic analysis revealed that SisEndoMS overexpression led to upregulation of distinct gene including the CRISPR-Cas IIIB system, methyltransferases, and glycosyltransferases, which are mainly localized to specific regions in the chromosome. Collectively, our results support that EndoMS proteins represent a noncanonical DNA repair pathway in Archaea. The mechanism of the mismatch repair pathway in Sulfolobus which have a single chromosome is discussed.
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Affiliation(s)
- Sohail Ahmad
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Qihong Huang
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Jinfeng Ni
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yuanxi Xiao
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yunfeng Yang
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yulong Shen
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
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White MF, Allers T. DNA repair in the archaea-an emerging picture. FEMS Microbiol Rev 2018; 42:514-526. [PMID: 29741625 DOI: 10.1093/femsre/fuy020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/02/2018] [Indexed: 12/12/2022] Open
Abstract
There has long been a fascination in the DNA repair pathways of archaea, for two main reasons. Firstly, many archaea inhabit extreme environments where the rate of physical damage to DNA is accelerated. These archaea might reasonably be expected to have particularly robust or novel DNA repair pathways to cope with this. Secondly, the archaea have long been understood to be a lineage distinct from the bacteria, and to share a close relationship with the eukarya, particularly in their information processing systems. Recent discoveries suggest the eukarya arose from within the archaeal domain, and in particular from lineages related to the TACK superphylum and Lokiarchaea. Thus, archaeal DNA repair proteins and pathways can represent a useful model system. This review focuses on recent advances in our understanding of archaeal DNA repair processes including base excision repair, nucleotide excision repair, mismatch repair and double-strand break repair. These advances are discussed in the context of the emerging picture of the evolution and relationship of the three domains of life.
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Affiliation(s)
- Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, Fife KY16 9ST, UK
| | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK
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5
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The essential genome of the crenarchaeal model Sulfolobus islandicus. Nat Commun 2018; 9:4908. [PMID: 30464174 PMCID: PMC6249222 DOI: 10.1038/s41467-018-07379-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/24/2018] [Indexed: 11/27/2022] Open
Abstract
Sulfolobus islandicus is a model microorganism in the TACK superphylum of the Archaea, a key lineage in the evolutionary history of cells. Here we report a genome-wide identification of the repertoire of genes essential to S. islandicus growth in culture. We confirm previous targeted gene knockouts, uncover the non-essentiality of functions assumed to be essential to the Sulfolobus cell, including the proteinaceous S-layer, and highlight essential genes whose functions are yet to be determined. Phyletic distributions illustrate the potential transitions that may have occurred during the evolution of this archaeal microorganism, and highlight sets of genes that may have been associated with each transition. We use this comparative context as a lens to focus future research on archaea-specific uncharacterized essential genes that may provide valuable insights into the evolutionary history of cells. Sulfolobus islandicus is a model organism within the TACK superphylum of the Archaea. Here, the authors perform a genome-wide analysis of essential genes in this organism, show that the proteinaceous S-layer is not essential, and explore potential stages of evolution of the essential gene repertoire in Archaea.
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6
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Zhai B, DuPrez K, Han X, Yuan Z, Ahmad S, Xu C, Gu L, Ni J, Fan L, Shen Y. The archaeal ATPase PINA interacts with the helicase Hjm via its carboxyl terminal KH domain remodeling and processing replication fork and Holliday junction. Nucleic Acids Res 2018; 46:6627-6641. [PMID: 29846688 PMCID: PMC6061704 DOI: 10.1093/nar/gky451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/05/2018] [Accepted: 05/09/2018] [Indexed: 11/27/2022] Open
Abstract
PINA is a novel ATPase and DNA helicase highly conserved in Archaea, the third domain of life. The PINA from Sulfolobus islandicus (SisPINA) forms a hexameric ring in crystal and solution. The protein is able to promote Holliday junction (HJ) migration and physically and functionally interacts with Hjc, the HJ specific endonuclease. Here, we show that SisPINA has direct physical interaction with Hjm (Hel308a), a helicase presumably targeting replication forks. In vitro biochemical analysis revealed that Hjm, Hjc, and SisPINA are able to coordinate HJ migration and cleavage in a concerted way. Deletion of the carboxyl 13 amino acid residues impaired the interaction between SisPINA and Hjm. Crystal structure analysis showed that the carboxyl 70 amino acid residues fold into a type II KH domain which, in other proteins, functions in binding RNA or ssDNA. The KH domain not only mediates the interactions of PINA with Hjm and Hjc but also regulates the hexameric assembly of PINA. Our results collectively suggest that SisPINA, Hjm and Hjc work together to function in replication fork regression, HJ formation and HJ cleavage.
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Affiliation(s)
- Binyuan Zhai
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Kevin DuPrez
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
| | - Xiaoyun Han
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Zenglin Yuan
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Sohail Ahmad
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Cheng Xu
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Lichuan Gu
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
| | - Li Fan
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Microbiology and Biotechnology Institute, Shandong University, 72 Binhai Road, Jimo, Qingdao, Shandong, 266237, P.R. China
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Northall SJ, Buckley R, Jones N, Penedo JC, Soultanas P, Bolt EL. DNA binding and unwinding by Hel308 helicase requires dual functions of a winged helix domain. DNA Repair (Amst) 2017; 57:125-132. [DOI: 10.1016/j.dnarep.2017.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 12/23/2022]
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Genetic technologies for extremely thermophilic microorganisms of Sulfolobus, the only genetically tractable genus of crenarchaea. SCIENCE CHINA-LIFE SCIENCES 2017; 60:370-385. [DOI: 10.1007/s11427-016-0355-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 12/18/2016] [Indexed: 12/26/2022]
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9
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Song X, Huang Q, Ni J, Yu Y, Shen Y. Knockout and functional analysis of two DExD/H-box family helicase genes in Sulfolobus islandicus REY15A. Extremophiles 2016; 20:537-46. [PMID: 27290726 DOI: 10.1007/s00792-016-0847-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/31/2016] [Indexed: 01/05/2023]
Abstract
DExD/H-box helicases represent the largest family of helicases. They belong to superfamily 2 helicases and participate in nucleotide metabolism, ribosome biogenesis, and nucleocytoplasmic transport. The biochemical properties and structures of some DExD/H-box helicases in the archaea have been documented, but many of them have not been characterized; and reports on in vivo functional analyses are limited. In this study, we attempted gene knockout of 8 putative DExD/H-box helicases in Sulfolobus islandicus REY15A and obtained two deletion mutants, SiRe_0681 and SiRe_1605. We determined that ΔSiRe_0681 grew faster than wild type cells in the presence of methyl methanesulfonate (MMS). Flow cytometry analysis showed that this strain had fewer G1/S phase cells than the wild type, and the genes coding for cell division proteins were up-regulated. The stain ΔSiRe_1605 was more sensitive to MMS than the wild type cell, and many nucleotide metabolism and DNA repair enzymes were found to be down-regulated. Intriguingly, deletion of either gene led to silencing simultaneously of over 80 genes located at a specific region. This study provides a novel insight into the in vivo functions of predicted DExD/H-box family helicases in the archaea.
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Affiliation(s)
- Xueguo Song
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China
| | - Qihong Huang
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China
| | - Yang Yu
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China.
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10
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Song X, Ni J, Shen Y. Structure-Based Genetic Analysis of Hel308a in the Hyperthermophilic Archaeon Sulfolobus islandicus. J Genet Genomics 2016; 43:405-13. [PMID: 27317310 DOI: 10.1016/j.jgg.2016.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/06/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
Abstract
In archaea, the HEL308 homolog Hel308a (or Hjm) is implicated in stalled replication fork repair. The biochemical properties and structures of Hjm homologs are well documented, but in vivo mechanistic information is limited. Herein, a structure-based functional analysis of Hjm was performed in the genetically tractable hyperthermophilic archaeon, Sulfolobus islandicus. Results showed that domain V and residues within it, which affect Hjm activity and regulation, are essential and that the domain V-truncated mutants and site-directed mutants within domain V cannot complement hjm chromosomal deletion. Chromosomal hjm deletion can be complemented by ectopic expression of hjm under the control of its native promoter but not an artificial arabinose promoter. Cellular Hjm levels are kept constant under ultraviolet (UV) and methyl methanesulfonate (MMS) treatment conditions in a strain carrying a plasmid to induce Hjm overexpression. These results suggest that Hjm expression and activity are tightly controlled, probably at the translational level.
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Affiliation(s)
- Xueguo Song
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
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11
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Chamieh H, Ibrahim H, Kozah J. Genome-wide identification of SF1 and SF2 helicases from archaea. Gene 2015; 576:214-28. [PMID: 26456193 DOI: 10.1016/j.gene.2015.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 08/13/2015] [Accepted: 10/04/2015] [Indexed: 11/26/2022]
Abstract
Archaea microorganisms have long been used as model organisms for the study of protein molecular machines. Archaeal proteins are particularly appealing to study since archaea, even though prokaryotic, possess eukaryotic-like cellular processes. Super Family I (SF1) and Super Family II (SF2) helicase families have been studied in many model organisms, little is known about their presence and distribution in archaea. We performed an exhaustive search of homologs of SF1 and SF2 helicase proteins in 95 complete archaeal genomes. In the present study, we identified the complete sets of SF1 and SF2 helicases in archaea. Comparative analysis between archaea, human and the bacteria E. coli SF1 and SF2 helicases, resulted in the identification of seven helicase families conserved among representatives of the domains of life. This analysis suggests that these helicase families are highly conserved throughout evolution. We highlight the conserved motifs of each family and characteristic domains of the detected families. Distribution of SF1/SF2 families show that Ski2-like, Lhr, Sfth and Rad3-like helicases are ubiquitous among archaeal genomes while the other families are specific to certain archaeal groups. We also report the presence of a novel SF2 helicase specific to archaea domain named Archaea Specific Helicase (ASH). Phylogenetic analysis indicated that ASH has evolved in Euryarchaeota and is evolutionary related to the Ski2-like family with specific characteristic domains. Our study provides the first exhaustive analysis of SF1 and SF2 helicases from archaea. It expands the variety of SF1 and SF2 archaeal helicases known to exist to date and provides a starting point for new biochemical and genetic studies needed to validate their biological functions.
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Affiliation(s)
- Hala Chamieh
- Faculty of Science, Department of Biology, Lebanese University, Tripoli, Lebanon; Centre AZM pour la Recherche en Biotechnologie et ses Applications, Laboratoire de Biotechnologie Appliquée, Ecole Doctorale Sciences et Technologies, Mitein Street, Tripoli, Lebanon.
| | - Hiba Ibrahim
- Faculty of Science, Department of Environmental and Biological Science, Beirut Arab University, Tripoli, Lebanon
| | - Juliana Kozah
- Faculty of Science, Université Saint Esprit de Kaslik, Jounieh, Lebanon
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Understanding DNA Repair in Hyperthermophilic Archaea: Persistent Gaps and Other Reasons to Focus on the Fork. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2015; 2015:942605. [PMID: 26146487 PMCID: PMC4471258 DOI: 10.1155/2015/942605] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/21/2015] [Indexed: 11/17/2022]
Abstract
Although hyperthermophilic archaea arguably have a great need for efficient DNA repair, they lack members of several DNA repair protein families broadly conserved among bacteria and eukaryotes. Conversely, the putative DNA repair genes that do occur in these archaea often do not generate the expected phenotype when deleted. The prospect that hyperthermophilic archaea have some unique strategies for coping with DNA damage and replication errors has intellectual and technological appeal, but resolving this question will require alternative coping mechanisms to be proposed and tested experimentally. This review evaluates a combination of four enigmatic properties that distinguishes the hyperthermophilic archaea from all other organisms: DNA polymerase stalling at dU, apparent lack of conventional NER, lack of MutSL homologs, and apparent essentiality of homologous recombination proteins. Hypothetical damage-coping strategies that could explain this set of properties may provide new starting points for efforts to define how archaea differ from conventional models of DNA repair and replication fidelity.
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Huang Q, Liu L, Liu J, Ni J, She Q, Shen Y. Efficient 5'-3' DNA end resection by HerA and NurA is essential for cell viability in the crenarchaeon Sulfolobus islandicus. BMC Mol Biol 2015; 16:2. [PMID: 25880130 PMCID: PMC4351679 DOI: 10.1186/s12867-015-0030-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 01/26/2015] [Indexed: 12/31/2022] Open
Abstract
Background ATPase/Helicases and nucleases play important roles in homologous recombination repair (HRR). Many of the mechanistic details relating to these enzymes and their function in this fundamental and complicated DNA repair process remain poorly understood in archaea. Here we employed Sulfolobus islandicus, a hyperthermophilic archaeon, as a model to investigate the in vivo functions of the ATPase/helicase HerA, the nuclease NurA, and their associated proteins Mre11 and Rad50. Results We revealed that each of the four genes in the same operon, mre11, rad50, herA, and nurA, are essential for cell viability by a mutant propagation assay. A genetic complementation assay with mutant proteins was combined with biochemical characterization demonstrating that the ATPase activity of HerA, the interaction between HerA and NurA, and the efficient 5′-3′ DNA end resection activity of the HerA-NurA complex are essential for cell viability. NurA and two other putative HRR proteins: a PIN (PilT N-terminal)-domain containing ATPase and the Holliday junction resolvase Hjc, were co-purified with a chromosomally encoded N-His-HerA in vivo. The interactions of HerA with the ATPase and Hjc were further confirmed by in vitro pull down. Conclusion Efficient 5′-3′ DNA end resection activity of the HerA-NurA complex contributes to necessity of HerA and NurA in Sulfolobus, which is crucial to yield a 3′-overhang in HRR. HerA may have additional binding partners in cells besides NurA. Electronic supplementary material The online version of this article (doi:10.1186/s12867-015-0030-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qihong Huang
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, P. R. China. .,Archaea Centre, Department of Biology, University of Copenhagen, Ole MaaløesVej 5, Copenhagen N, DK-2200, Denmark.
| | - Linlin Liu
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, P. R. China.
| | - Junfeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, P. R. China.
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, P. R. China.
| | - Qunxin She
- Archaea Centre, Department of Biology, University of Copenhagen, Ole MaaløesVej 5, Copenhagen N, DK-2200, Denmark.
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, P. R. China.
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14
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Huang Q, Li Y, Zeng C, Song T, Yan Z, Ni J, She Q, Shen Y. Genetic analysis of the Holliday junction resolvases Hje and Hjc in Sulfolobus islandicus. Extremophiles 2015; 19:505-14. [PMID: 25644236 DOI: 10.1007/s00792-015-0734-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/20/2015] [Indexed: 11/26/2022]
Abstract
The in vivo functions of Hje and Hjc, two Holliday junction resolvases in Sulfolobus islandicus were investigated. We found that deletion of either hje or hjc had no effect on normal cell growth, while deletion of both hje and hjc is lethal. Although Hjc is the conserved resolvase in all archaea, the hje deletion rather than hjc deletion rendered cells more sensitive to DNA-damaging agents such as hydroxyurea, cisplatin, and methyl methanesulfonate than the wild type (WT). Intriguingly, the sensitivity of Δhje could not be rescued by ectopic expression of Hje from a plasmid and Hje overexpression slowed growth and large cells appeared with more than two genome equivalents. We showed that Hje was maintained at a low level in WT cells. Furthermore, transcriptomic microarray analysis revealed that the abundance of transcripts of many genes including those involved in DNA replication, repair, transcription regulation, and cell division changed drastically in the Hje-overexpressed strain. However, only limited genes were up- or downregulated in the hje deletion strain. Our findings collectively suggest that Hje is the primary resolvase involved in DNA repair and its expression must be tightly controlled in cells.
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Affiliation(s)
- Qihong Huang
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, People's Republic of China
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15
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Han W, Shen Y, She Q. Nanobiomotors of archaeal DNA repair machineries: current research status and application potential. Cell Biosci 2014; 4:32. [PMID: 24995126 PMCID: PMC4080772 DOI: 10.1186/2045-3701-4-32] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 06/13/2014] [Indexed: 11/10/2022] Open
Abstract
Nanobiomotors perform various important functions in the cell, and they also emerge as potential vehicle for drug delivery. These proteins employ conserved ATPase domains to convert chemical energy to mechanical work and motion. Several archaeal nucleic acid nanobiomotors, such as DNA helicases that unwind double-stranded DNA molecules during DNA damage repair, have been characterized in details. XPB, XPD and Hjm are SF2 family helicases, each of which employs two ATPase domains for ATP binding and hydrolysis to drive DNA unwinding. They also carry additional specific domains for substrate binding and regulation. Another helicase, HerA, forms a hexameric ring that may act as a DNA-pumping enzyme at the end processing of double-stranded DNA breaks. Common for all these nanobiomotors is that they contain ATPase domain that adopts RecA fold structure. This structure is characteristic for RecA/RadA family proteins and has been studied in great details. Here we review the structural analyses of these archaeal nucleic acid biomotors and the molecular mechanisms of how ATP binding and hydrolysis promote the conformation change that drives mechanical motion. The application potential of archaeal nanobiomotors in drug delivery has been discussed.
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Affiliation(s)
- Wenyuan Han
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China ; Archaeal Centre, Department of Biology, University of Copenhagen, Copenhagen Biocenter, Copenhagen, Denmark
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
| | - Qunxin She
- Archaeal Centre, Department of Biology, University of Copenhagen, Copenhagen Biocenter, Copenhagen, Denmark
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16
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Genetic manipulation in Sulfolobus islandicus and functional analysis of DNA repair genes. Biochem Soc Trans 2013; 41:405-10. [PMID: 23356319 DOI: 10.1042/bst20120285] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recently, a novel gene-deletion method was developed for the crenarchaeal model Sulfolobus islandicus, which is a suitable tool for addressing gene essentiality in depth. Using this technique, we have investigated functions of putative DNA repair genes by constructing deletion mutants and studying their phenotype. We found that this archaeon may not encode a eukarya-type of NER (nucleotide excision repair) pathway because depleting each of the eukaryal NER homologues XPD, XPB and XPF did not impair the DNA repair capacity in their mutants. However, among seven homologous recombination proteins, including RadA, Hel308/Hjm, Rad50, Mre11, HerA, NurA and Hjc, only the Hjc nuclease is dispensable for cell viability. Sulfolobus encodes redundant BER (base excision repair) enzymes such as two uracil DNA glycosylases and two putative apurinic/apyrimidinic lyases, but inactivation of one of the redundant enzymes already impaired cell growth, highlighting their important roles in archaeal DNA repair. Systematically characterizing these mutants and generating mutants lacking two or more DNA repair genes will yield further insights into the genetic mechanisms of DNA repair in this model organism.
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17
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An archaeal protein evolutionarily conserved in prokaryotes is a zinc-dependent metalloprotease. Biosci Rep 2013; 32:609-18. [PMID: 22950735 PMCID: PMC3497727 DOI: 10.1042/bsr20120074] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A putative protease gene (tldD) was previously identified from studying tolerance of letD encoding the CcdB toxin of a toxin–antidote system of the F plasmid in Escherichia coli. While this gene is evolutionarily conserved in archaea and bacteria, the proteolytic activity of encoded proteins remained to be demonstrated experimentally. Here we studied Sso0660, an archaeal TldD homologue encoded in Sulfolobus solfataricus by overexpression of the recombinant protein and characterization of the purified enzyme. We found that the enzyme is active in degrading azocasein and FITC–BSA substrates. Protease inhibitor studies showed that EDTA and o-phenanthroline, two well-known metalloprotease inhibitors, either abolished completely or strongly inhibited the enzyme activity, and flame spectrometric analysis showed that a zinc ion is a cofactor of the protease. Furthermore, the protein forms disulfide bond via the Cys416 residue, yielding protein dimer that is the active form of the enzyme. These results establish for the first time that tidD genes encode zinc-containing proteases, classifying them as a family in the metalloprotease class.
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