1
|
Zakharova K, Liu M, Greenwald JR, Caldwell BC, Qi Z, Wysocki VH, Bell CE. Structural Basis for the Interaction of Redβ Single-Strand Annealing Protein with Escherichia coli Single-Stranded DNA-Binding Protein. J Mol Biol 2024; 436:168590. [PMID: 38663547 DOI: 10.1016/j.jmb.2024.168590] [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] [Received: 02/22/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 05/07/2024]
Abstract
Redβ is a protein from bacteriophage λ that binds to single-stranded DNA (ssDNA) to promote the annealing of complementary strands. Together with λ-exonuclease (λ-exo), Redβ is part of a two-component DNA recombination system involved in multiple aspects of genome maintenance. The proteins have been exploited in powerful methods for bacterial genome engineering in which Redβ can anneal an electroporated oligonucleotide to a complementary target site at the lagging strand of a replication fork. Successful annealing in vivo requires the interaction of Redβ with E. coli single-stranded DNA-binding protein (SSB), which coats the ssDNA at the lagging strand to coordinate access of numerous replication proteins. Previous mutational analysis revealed that the interaction between Redβ and SSB involves the C-terminal domain (CTD) of Redβ and the C-terminal tail of SSB (SSB-Ct), the site for binding of numerous host proteins. Here, we have determined the x-ray crystal structure of Redβ CTD in complex with a peptide corresponding to the last nine residues of SSB (MDFDDDIPF). Formation of the complex is predominantly mediated by hydrophobic interactions between two phenylalanine side chains of SSB (Phe-171 and Phe-177) and an apolar groove on the CTD, combined with electrostatic interactions between the C-terminal carboxylate of SSB and Lys-214 of the CTD. Mutation of any of these residues to alanine significantly disrupts the interaction of full-length Redβ and SSB proteins. Structural knowledge of this interaction will help to expand the utility of Redβ-mediated recombination to a wider range of bacterial hosts for applications in synthetic biology.
Collapse
Affiliation(s)
- Katerina Zakharova
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA
| | - Mengqi Liu
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA
| | - Jacelyn R Greenwald
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Brian C Caldwell
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
| | - Zihao Qi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Vicki H Wysocki
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Charles E Bell
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
2
|
Bonde NJ, Kozlov AG, Cox MM, Lohman TM, Keck JL. Molecular insights into the prototypical single-stranded DNA-binding protein from E. coli. Crit Rev Biochem Mol Biol 2024:1-29. [PMID: 38770626 DOI: 10.1080/10409238.2024.2330372] [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: 11/28/2023] [Accepted: 03/11/2024] [Indexed: 05/22/2024]
Abstract
The SSB protein of Escherichia coli functions to bind single-stranded DNA wherever it occurs during DNA metabolism. Depending upon conditions, SSB occurs in several different binding modes. In the course of its function, SSB diffuses on ssDNA and transfers rapidly between different segments of ssDNA. SSB interacts with many other proteins involved in DNA metabolism, with 22 such SSB-interacting proteins, or SIPs, defined to date. These interactions chiefly involve the disordered and conserved C-terminal residues of SSB. When not bound to ssDNA, SSB can aggregate to form a phase-separated biomolecular condensate. Current understanding of the properties of SSB and the functional significance of its many intermolecular interactions are summarized in this review.
Collapse
Affiliation(s)
- Nina J Bonde
- Department of Biochemistry, University of WI-Madison, Madison, Wisconsin, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alexander G Kozlov
- Department of Biochemistry and Molecular Biophysics, WA University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Michael M Cox
- Department of Biochemistry, University of WI-Madison, Madison, Wisconsin, USA
| | - Timothy M Lohman
- Department of Biochemistry and Molecular Biophysics, WA University in St. Louis School of Medicine, St. Louis, MO, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|
3
|
Pipalović G, Filić Ž, Ćehić M, Paradžik T, Zahradka K, Crnolatac I, Vujaklija D. Impact of C-terminal domains of paralogous single-stranded DNA binding proteins from Streptomyces coelicolor on their biophysical properties and biological functions. Int J Biol Macromol 2024; 268:131544. [PMID: 38614173 DOI: 10.1016/j.ijbiomac.2024.131544] [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] [Received: 02/12/2024] [Revised: 04/03/2024] [Accepted: 04/10/2024] [Indexed: 04/15/2024]
Abstract
Single-stranded DNA-binding proteins (SSB) are crucial in DNA metabolism. While Escherichia coli SSB is extensively studied, the significance of its C-terminal domain has only recently emerged. This study explored the significance of C-domains of two paralogous Ssb proteins in S. coelicolor. Mutational analyses of C-domains uncovered a novel role of SsbA during sporulation-specific cell division and demonstrated that the C-tip is non-essential for survival. In vitro methods revealed altered biophysical and biochemical properties of Ssb proteins with modified C-domains. Determined hydrodynamic properties suggested that the C-domains of SsbA and SsbB occupy a globular position proposed to mediate cooperative binding. Only SsbA was found to form biomolecular condensates independent of the C-tip. Interestingly, the truncated C-domain of SsbA increased the molar enthalpy of unfolding. Additionally, calorimetric titrations revealed that C-domain mutations affected ssDNA binding. Moreover, this analysis showed that the SsbA C-tip aids binding most likely by regulating the position of the flexible C-domain. It also highlighted ssDNA-induced conformational mobility restrictions of all Ssb variants. Finally, the gel mobility shift assay confirmed that the intrinsically disordered linker is essential for cooperative binding of SsbA. These findings highlight the important role of the C-domain in the functioning of SsbA and SsbB proteins.
Collapse
Affiliation(s)
- Goran Pipalović
- Division of Physical Chemistry, Institute Ruđer Bošković, Zagreb, Croatia
| | - Želimira Filić
- Division of Physical Chemistry, Institute Ruđer Bošković, Zagreb, Croatia
| | - Mirsada Ćehić
- Division of Physical Chemistry, Institute Ruđer Bošković, Zagreb, Croatia
| | - Tina Paradžik
- Division of Physical Chemistry, Institute Ruđer Bošković, Zagreb, Croatia
| | - Ksenija Zahradka
- Division of Molecular Biology, Institute Ruđer Bošković, Zagreb, Croatia
| | - Ivo Crnolatac
- Division of Organic Chemistry and Biochemistry, Institute Ruđer Bošković, Zagreb, Croatia.
| | - Dušica Vujaklija
- Division of Physical Chemistry, Institute Ruđer Bošković, Zagreb, Croatia.
| |
Collapse
|
4
|
Sandler SJ, Bonde NJ, Wood EA, Cox MM, Keck JL. The intrinsically disordered linker in the single-stranded DNA-binding protein influences DNA replication restart and recombination pathways in Escherichia coli K-12. J Bacteriol 2024; 206:e0033023. [PMID: 38470036 PMCID: PMC11025327 DOI: 10.1128/jb.00330-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/21/2024] [Indexed: 03/13/2024] Open
Abstract
Tetrameric single-stranded (ss) DNA-binding proteins (SSBs) stabilize ssDNA intermediates formed during genome maintenance reactions in Bacteria. SSBs also recruit proteins important for these processes through direct SSB-protein interactions, including proteins involved in DNA replication restart and recombination processes. SSBs are composed of an N-terminal oligomerization and ssDNA-binding domain, a C-terminal acidic tip that mediates SSB-protein interactions, and an internal intrinsically disordered linker (IDL). Deletions and insertions into the IDL are well tolerated with few phenotypes, although the largest deletions and insertions exhibit some sensitivity to DNA-damaging agents. To define specific DNA metabolism processes dependent on IDL length, ssb mutants that lack 16, 26, 37, or 47 residues of the 57-residue IDL were tested for synthetic phenotypes with mutations in DNA replication restart or recombination genes. We also tested the impact of integrating a fluorescent domain within the SSB IDL using an ssb::mTur2 insertion mutation. Only the largest deletion tested or the insertion mutation causes sensitivity in any of the pathways. Mutations in two replication restart pathways (PriA-B1 and PriA-C) showed synthetic lethalities or small colony phenotypes with the largest deletion or insertion mutations. Recombination gene mutations del(recBCD) and del(ruvABC) show synthetic phenotypes only when combined with the largest ssb deletion. These results suggest that a minimum IDL length is important in some genome maintenance reactions in Escherichia coli. These include pathways involving PriA-PriB1, PriA-PriC, RecFOR, and RecG. The mTur2 insertion in the IDL may also affect SSB interactions in some processes, particularly the PriA-PriB1 and PriA-PriC replication restart pathways.IMPORTANCEssb is essential in Escherichia coli due to its roles in protecting ssDNA and coordinating genome maintenance events. While the DNA-binding core and acidic tip have well-characterized functions, the purpose of the intrinsically disordered linker (IDL) is poorly understood. In vitro studies have revealed that the IDL is important for cooperative ssDNA binding and phase separation. However, single-stranded (ss) DNA-binding protein (SSB) variants with large deletions and insertions in the IDL support normal cell growth. We find that the PriA-PriB1 and PriA-C replication restart, as well as the RecFOR- and RecG-dependent recombination, pathways are sensitive to IDL length. This suggests that cooperativity, phase separation, or a longer spacer between the core and acidic tip of SSB may be important for specific cellular functions.
Collapse
Affiliation(s)
- Steven J. Sandler
- Department of Microbiology, University of Massachusetts at Amherst, Amherst, Massachusetts, USA
| | - Nina J. Bonde
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
- Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Elizabeth A. Wood
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Michael M. Cox
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - James L. Keck
- Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin, USA
| |
Collapse
|
5
|
Wei L, Zhu D, Cheng Q, Gao Z, Wang H, Qiu J. Aptamer-Based fluorescent DNA biosensor in antibiotics detection. Food Res Int 2024; 179:114005. [PMID: 38342532 DOI: 10.1016/j.foodres.2024.114005] [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] [Received: 11/14/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 02/13/2024]
Abstract
The inappropriate employment of antibiotics across diverse industries has engendered profound apprehensions concerning their cumulative presence within human bodies and food commodities. Consequently, many nations have instituted stringent measures limiting the admissible quantities of antibiotics in food items. Nonetheless, conventional techniques employed for antibiotic detection prove protracted and laborious, prompting a dire necessity for facile, expeditious, and uncomplicated detection methodologies. In this regard, aptamer-based fluorescent DNA biosensors (AFBs) have emerged as a sanguine panacea to surmount the limitations of traditional detection modalities. These ingenious biosensors harness the binding prowess of aptamers, singular strands of DNA/RNA, to selectively adhere to specific target antibiotics. Notably, the AFBs demonstrate unparalleled selectivity, affinity, and sensitivity in detecting antibiotics. This comprehensive review meticulously expounds upon the strides achieved in AFBs for antibiotic detection, particularly emphasizing the labeling modality and the innovative free-label approach. It also elucidates the design principles behind a diverse array of AFBs. Additionally, a succinct survey of signal amplification strategies deployed within these biosensors is provided. The central objective of this review is to apprise researchers from diverse disciplines of the contemporary trends in AFBs for antibiotic detection. By doing so, it aspires to instigate a concerted endeavor toward the development of heightened sensitivity and pioneering AFBs, thereby contributing to the perpetual advancement of antibiotic detection methodologies.
Collapse
Affiliation(s)
- Luke Wei
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China
| | - Dingze Zhu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China
| | - Qiuyue Cheng
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China
| | - Zihan Gao
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China
| | - Honglei Wang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China
| | - Jieqiong Qiu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China.
| |
Collapse
|
6
|
Zhang J, Chen F, Tang M, Xu W, Tian Y, Liu Z, Shu Y, Yang H, Zhu Q, Lu X, Peng B, Liu X, Xu X, Gullerova M, Zhu WG. The ARID1A-METTL3-m6A axis ensures effective RNase H1-mediated resolution of R-loops and genome stability. Cell Rep 2024; 43:113779. [PMID: 38358891 DOI: 10.1016/j.celrep.2024.113779] [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] [Received: 07/12/2023] [Revised: 12/02/2023] [Accepted: 01/26/2024] [Indexed: 02/17/2024] Open
Abstract
R-loops are three-stranded structures that can pose threats to genome stability. RNase H1 precisely recognizes R-loops to drive their resolution within the genome, but the underlying mechanism is unclear. Here, we report that ARID1A recognizes R-loops with high affinity in an ATM-dependent manner. ARID1A recruits METTL3 and METTL14 to the R-loop, leading to the m6A methylation of R-loop RNA. This m6A modification facilitates the recruitment of RNase H1 to the R-loop, driving its resolution and promoting DNA end resection at DSBs, thereby ensuring genome stability. Depletion of ARID1A, METTL3, or METTL14 leads to R-loop accumulation and reduced cell survival upon exposure to cytotoxic agents. Therefore, ARID1A, METTL3, and METTL14 function in a coordinated, temporal order at DSB sites to recruit RNase H1 and to ensure efficient R-loop resolution. Given the association of high ARID1A levels with resistance to genotoxic therapies in patients, these findings open avenues for exploring potential therapeutic strategies for cancers with ARID1A abnormalities.
Collapse
Affiliation(s)
- Jun Zhang
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Feng Chen
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Ming Tang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Wenchao Xu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Yuan Tian
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Zhichao Liu
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Yuxin Shu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Hui Yang
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Qian Zhu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Xiaopeng Lu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Bin Peng
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Cell Biology and Medical Genetics, Shenzhen University Medical School, Shenzhen 518055, China
| | - Xiangyu Liu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China
| | - Xingzhi Xu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Cell Biology and Medical Genetics, Shenzhen University Medical School, Shenzhen 518055, China
| | - Monika Gullerova
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Wei-Guo Zhu
- International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen 518055, China; Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518055, China; School of Basic Medical Sciences, Wannan Medical College, Wuhu, Anhui 241002, China; Department of Biochemistry and Molecular Biology, Peking University Health Science Centre, Beijing 100191, China.
| |
Collapse
|
7
|
Cherry ME, Dubiel K, Henry C, Wood EA, Revitt-Mills SA, Keck JL, Cox MM, van Oijen AM, Ghodke H, Robinson A. Spatiotemporal Dynamics of Single-stranded DNA Intermediates in Escherichia coli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539320. [PMID: 37214928 PMCID: PMC10197600 DOI: 10.1101/2023.05.08.539320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Single-stranded DNA gaps form within the E. coli chromosome during replication, repair and recombination. However, information about the extent of ssDNA creation in the genome is limited. To complement a recent whole-genome sequencing study revealing ssDNA gap genomic distribution, size, and frequency, we used fluorescence microscopy to monitor the spatiotemporal dynamics of single-stranded DNA within live E. coli cells. The ssDNA was marked by a functional fluorescent protein fusion of the SSB protein that replaces the wild type SSB. During log-phase growth the SSB fusion produces a mixture of punctate foci and diffuse fluorescence spread throughout the cytosol. Many foci are clustered. Fluorescent markers of DNA polymerase III frequently co-localize with SSB foci, often localizing to the outer edge of the large SSB features. Novel SSB-enriched features form and resolve regularly during normal growth. UV irradiation induces a rapid increase in SSB foci intensity and produces large features composed of multiple partially overlapping foci. The results provide a critical baseline for further exploration of ssDNA generation during DNA metabolism. Alterations in the patterns seen in a mutant lacking RecB function tentatively suggest associations of particular SSB features with the repair of double strand breaks and post-replication gaps.
Collapse
|
8
|
Bonde NJ, Henry C, Wood EA, Cox MM, Keck J. Interaction with the carboxy-terminal tip of SSB is critical for RecG function in E. coli. Nucleic Acids Res 2023; 51:3735-3753. [PMID: 36912097 PMCID: PMC10164576 DOI: 10.1093/nar/gkad162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/17/2023] [Accepted: 03/03/2023] [Indexed: 03/14/2023] Open
Abstract
In Escherichia coli, the single-stranded DNA-binding protein (SSB) acts as a genome maintenance organizational hub by interacting with multiple DNA metabolism proteins. Many SSB-interacting proteins (SIPs) form complexes with SSB by docking onto its carboxy-terminal tip (SSB-Ct). An alternative interaction mode in which SIPs bind to PxxP motifs within an intrinsically-disordered linker (IDL) in SSB has been proposed for the RecG DNA helicase and other SIPs. Here, RecG binding to SSB and SSB peptides was measured in vitro and the RecG/SSB interface was identified. The results show that RecG binds directly and specifically to the SSB-Ct, and not the IDL, through an evolutionarily conserved binding site in the RecG helicase domain. Mutations that block RecG binding to SSB sensitize E. coli to DNA damaging agents and induce the SOS DNA-damage response, indicating formation of the RecG/SSB complex is important in vivo. The broader role of the SSB IDL is also investigated. E. coli ssb mutant strains encoding SSB IDL deletion variants lacking all PxxP motifs retain wildtype growth and DNA repair properties, demonstrating that the SSB PxxP motifs are not major contributors to SSB cellular functions.
Collapse
Affiliation(s)
- Nina J Bonde
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Camille Henry
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Elizabeth A Wood
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Michael M Cox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
9
|
Osorio Garcia MA, Wood EA, Keck JL, Cox MM. Interaction with single-stranded DNA-binding protein (SSB) modulates Escherichia coli RadD DNA repair activities. J Biol Chem 2023; 299:104773. [PMID: 37142225 DOI: 10.1016/j.jbc.2023.104773] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/06/2023] Open
Abstract
The bacterial RadD enzyme is important for multiple genome maintenance pathways, including RecA DNA strand exchange and RecA-independent suppression of DNA crossover template switching. However, much remains unknown about the precise roles of RadD. One potential clue into RadD mechanisms is its direct interaction with the single-stranded DNA binding protein (SSB), which coats single-stranded DNA exposed during genome maintenance reactions in cells. Interaction with SSB stimulates the ATPase activity of RadD. To probe the mechanism and importance of RadD:SSB complex formation, we identified a pocket on RadD that is essential for binding SSB. In a mechanism shared with many other SSB-interacting proteins, RadD uses a hydrophobic pocket framed by basic residues to bind the C-terminal end of SSB. We found that RadD variants that substitute acidic residues for basic residues in the SSB binding site impair RadD:SSB complex formation and eliminate SSB stimulation of RadD ATPase activity in vitro. Additionally, mutant E. coli strains carrying charge reversal radD changes display increased sensitivity to DNA damaging agents synergistically with deletions of radA and recG, although the phenotypes of the SSB-binding radD mutants are not as severe as a full radD deletion. This suggests that cellular RadD requires an intact the interaction with SSB for full RadD function.
Collapse
Affiliation(s)
| | - Elizabeth A Wood
- Department of Biochemistry, University of Wisconsin, Madison, Madison, WI 53706
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706, USA.
| | - Michael M Cox
- Department of Biochemistry, University of Wisconsin, Madison, Madison, WI 53706.
| |
Collapse
|
10
|
Łazowski K, Faraz M, Vaisman A, Ashton NW, Jonczyk P, Fijalkowska IJ, Clausen AR, Woodgate R, Makiela-Dzbenska K. Strand specificity of ribonucleotide excision repair in Escherichia coli. Nucleic Acids Res 2023; 51:1766-1782. [PMID: 36762476 PMCID: PMC9976901 DOI: 10.1093/nar/gkad038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/03/2023] [Accepted: 01/12/2023] [Indexed: 02/11/2023] Open
Abstract
In Escherichia coli, replication of both strands of genomic DNA is carried out by a single replicase-DNA polymerase III holoenzyme (pol III HE). However, in certain genetic backgrounds, the low-fidelity TLS polymerase, DNA polymerase V (pol V) gains access to undamaged genomic DNA where it promotes elevated levels of spontaneous mutagenesis preferentially on the lagging strand. We employed active site mutants of pol III (pol IIIα_S759N) and pol V (pol V_Y11A) to analyze ribonucleotide incorporation and removal from the E. coli chromosome on a genome-wide scale under conditions of normal replication, as well as SOS induction. Using a variety of methods tuned to the specific properties of these polymerases (analysis of lacI mutational spectra, lacZ reversion assay, HydEn-seq, alkaline gel electrophoresis), we present evidence that repair of ribonucleotides from both DNA strands in E. coli is unequal. While RNase HII plays a primary role in leading-strand Ribonucleotide Excision Repair (RER), the lagging strand is subject to other repair systems (RNase HI and under conditions of SOS activation also Nucleotide Excision Repair). Importantly, we suggest that RNase HI activity can also influence the repair of single ribonucleotides incorporated by the replicase pol III HE into the lagging strand.
Collapse
Affiliation(s)
- Krystian Łazowski
- Laboratory of DNA Replication and Genome Stability, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Mahmood Faraz
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 40530, Sweden
| | - Alexandra Vaisman
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA
| | - Nicholas W Ashton
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA
| | - Piotr Jonczyk
- Laboratory of DNA Replication and Genome Stability, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Iwona J Fijalkowska
- Laboratory of DNA Replication and Genome Stability, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Anders R Clausen
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 40530, Sweden
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA
| | - Karolina Makiela-Dzbenska
- Laboratory of DNA Replication and Genome Stability, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| |
Collapse
|
11
|
Jia Y, Zhao S, Li D, Yang J, Yang L. Portable chemiluminescence optical fiber aptamer-based biosensors for analysis of multiple mycotoxins. Food Control 2023. [DOI: 10.1016/j.foodcont.2022.109361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
12
|
Newcomb ESP, Douma LG, Morris LA, Bloom LB. The Escherichia coli clamp loader rapidly remodels SSB on DNA to load clamps. Nucleic Acids Res 2022; 50:12872-12884. [PMID: 36511874 PMCID: PMC9825162 DOI: 10.1093/nar/gkac1169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022] Open
Abstract
Single-stranded DNA binding proteins (SSBs) avidly bind ssDNA and yet enzymes that need to act during DNA replication and repair are not generally impeded by SSB, and are often stimulated by SSB. Here, the effects of Escherichia coli SSB on the activities of the DNA polymerase processivity clamp loader were investigated. SSB enhances binding of the clamp loader to DNA by increasing the lifetime on DNA. Clamp loading was measured on DNA substrates that differed in length of ssDNA overhangs to permit SSB binding in different binding modes. Even though SSB binds DNA adjacent to single-stranded/double-stranded DNA junctions where clamps are loaded, the rate of clamp loading on DNA was not affected by SSB on any of the DNA substrates. Direct measurements of the relative timing of DNA-SSB remodeling and enzyme-DNA binding showed that the clamp loader rapidly remodels SSB on DNA such that SSB has little effect on DNA binding rates. However, when SSB was mutated to reduce protein-protein interactions with the clamp loader, clamp loading was inhibited by impeding binding of the clamp loader to DNA. Thus, protein-protein interactions between the clamp loader and SSB facilitate rapid DNA-SSB remodeling to allow rapid clamp loader-DNA binding and clamp loading.
Collapse
Affiliation(s)
- Elijah S P Newcomb
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610-0245, USA
| | - Lauren G Douma
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610-0245, USA
| | - Leslie A Morris
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610-0245, USA
| | - Linda B Bloom
- To whom correspondence should be addressed. Tel: +1 352 294 8379; Fax: +1 352 392 2953;
| |
Collapse
|
13
|
McLean EK, Nye TM, Lowder FC, Simmons LA. The Impact of RNA-DNA Hybrids on Genome Integrity in Bacteria. Annu Rev Microbiol 2022; 76:461-480. [PMID: 35655343 PMCID: PMC9527769 DOI: 10.1146/annurev-micro-102521-014450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
During the essential processes of DNA replication and transcription, RNA-DNA hybrid intermediates are formed that pose significant risks to genome integrity when left unresolved. To manage RNA-DNA hybrids, all cells rely on RNase H family enzymes that specifically cleave the RNA portion of the many different types of hybrids that form in vivo. Recent experimental advances have provided new insight into how RNA-DNA hybrids form and the consequences to genome integrity that ensue when persistent hybrids remain unresolved. Here we review the types of RNA-DNA hybrids, including R-loops, RNA primers, and ribonucleotide misincorporations, that form during DNA replication and transcription and discuss how each type of hybrid can contribute to genome instability in bacteria. Further, we discuss how bacterial RNase HI, HII, and HIII and bacterial FEN enzymes contribute to genome maintenance through the resolution of hybrids.
Collapse
Affiliation(s)
- Emma K McLean
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
| | - Taylor M Nye
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
- Current affiliation: Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Frances C Lowder
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
| | - Lyle A Simmons
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
| |
Collapse
|
14
|
Liu W, Han L, Song P, Sun H, Zhang C, Zou L, Cui J, Pan Q, Ren H. Complete genome sequencing of a Tequintavirus bacteriophage with a broad host range against Salmonella Abortus equi isolates from donkeys. Front Microbiol 2022; 13:938616. [PMID: 36051756 PMCID: PMC9424859 DOI: 10.3389/fmicb.2022.938616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/18/2022] [Indexed: 11/23/2022] Open
Abstract
Salmonella enterica subspecies enterica serovar abortus equi (S. Abortus equi) is the most common cause of abortion in mares. It has recently been found to cause abortion in donkeys more frequently in China. A novel virulent bacteriophage vB_SabS_Sds2 (hereafter designated as Sds2) was isolated from the feces of donkeys using a S. Abortus equi strain as a host. Phage Sds2 had an isometric polyhedral head and an uncontracted long tail, belonging to the Tequintavirus, Markadamsvirinae, Demerecviridae, Caudovirales. The genome of phage Sds2 was 114,770 bp, with a GC content of 40.26%. The genome contained 160 open reading frames (ORFs), and no ORFs were associated with pathogenicity, drug resistance, or lysogenization by sequence analysis. Both genome annotation and phylogenetic analysis indicated that phage Sds2 was highly similar to T5-like bacteriophages. Phage Sds2 could lyse 100% (30/30) of S. Abortus equi strains, 25.3% (24/95) of other serotypes of Salmonella strains, and 27.6% (8/29) of Escherichia coli strains using the double-layer agar plate method. The in vitro test showed that phage Sds2 had high bactericidal activity against S. Abortus equi at a wide range of MOIs. The in vivo test indicated that phage Sds2 had an inhibitory effect on abortion in mice challenged with S. Abortus equi. In general, phage Sds2 is a novel lytic phage with a wide host range and has the potential to prevent abortion caused by S. Abortus equi.
Collapse
Affiliation(s)
- Wenhua Liu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Letian Han
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Peng Song
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Huzhi Sun
- Qingdao Phagepharm Bio-tech Co., Ltd., Qingdao, Shandong, China
| | - Can Zhang
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Ling Zou
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Jiaqi Cui
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Qiang Pan
- Qingdao Phagepharm Bio-tech Co., Ltd., Qingdao, Shandong, China
- *Correspondence: Qiang Pan,
| | - Huiying Ren
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
- Huiying Ren,
| |
Collapse
|
15
|
Zhang L, Bernardo KD, Vickers TA, Tian J, Liang XH, Crooke ST. NAT10 and DDX21 Proteins Interact with RNase H1 and Affect the Performance of Phosphorothioate Oligonucleotides. Nucleic Acid Ther 2022; 32:280-299. [PMID: 35852833 PMCID: PMC9416547 DOI: 10.1089/nat.2021.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
RNase H1-dependent phosphorothioate oligonucleotides (PS-ASOs) have been developed to treat various diseases through specific degradation of target RNAs. Although many factors or features of RNA and PS-ASOs have been demonstrated to affect antisense activity of PS-ASOs, little is known regarding the roles of RNase H1-associated proteins in PS-ASO performance. In this study, we report that two nucleolar proteins, NAT10 and DDX21, interact with RNase H1 and affect the potency and safety of PS-ASOs. The interactions of these two proteins with RNase H1 were determined using BioID proximity labeling in cells and confirmed biochemically. Reduction of NAT10 and DDX21 decreased PS-ASO activity in cells, and purified NAT10 and DDX21 proteins enhanced RNase H1 cleavage rates, indicating that these two proteins facilitate RNase H1 endoribonuclease activity. Consistently, reduction of these proteins increased the levels of R-loops, and impaired pre-rRNA processing. In addition, reduction of the two proteins increased the cytotoxicity of toxic PS-ASOs, and treatment of toxic PS-ASOs also altered the localization of these proteins. Together, this study shows for the first time that NAT10 and DDX21 interact with RNase H1 protein and enhance its enzymatic activity, contributing to the potency and safety of PS-ASOs.
Collapse
Affiliation(s)
- Lingdi Zhang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Karla D. Bernardo
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Timothy A. Vickers
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Jun Tian
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Xue-hai Liang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Stanley T. Crooke
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| |
Collapse
|
16
|
Lee H, Cho H, Kim J, Lee S, Yoo J, Park D, Lee G. RNase H is an exo- and endoribonuclease with asymmetric directionality, depending on the binding mode to the structural variants of RNA:DNA hybrids. Nucleic Acids Res 2022; 50:1801-1814. [PMID: 34788459 PMCID: PMC8886854 DOI: 10.1093/nar/gkab1064] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/12/2021] [Accepted: 10/20/2021] [Indexed: 11/22/2022] Open
Abstract
RNase H is involved in fundamental cellular processes and is responsible for removing the short stretch of RNA from Okazaki fragments and the long stretch of RNA from R-loops. Defects in RNase H lead to embryo lethality in mice and Aicardi-Goutieres syndrome in humans, suggesting the importance of RNase H. To date, RNase H is known to be a non-sequence-specific endonuclease, but it is not known whether it performs other functions on the structural variants of RNA:DNA hybrids. Here, we used Escherichia coli RNase H as a model, and examined its catalytic mechanism and its substrate recognition modes, using single-molecule FRET. We discovered that RNase H acts as a processive exoribonuclease on the 3' DNA overhang side but as a distributive non-sequence-specific endonuclease on the 5' DNA overhang side of RNA:DNA hybrids or on blunt-ended hybrids. The high affinity of previously unidentified double-stranded (ds) and single-stranded (ss) DNA junctions flanking RNA:DNA hybrids may help RNase H find the hybrid substrates in long genomic DNA. Our study provides new insights into the multifunctionality of RNase H, elucidating unprecedented roles of junctions and ssDNA overhang on RNA:DNA hybrids.
Collapse
Affiliation(s)
- Hyunjee Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Single-Molecule Biology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - HyeokJin Cho
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Single-Molecule Biology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Jooyoung Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Sua Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Jungmin Yoo
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Single-Molecule Biology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Daeho Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Gwangrog Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Single-Molecule Biology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| |
Collapse
|
17
|
Bianco PR. The mechanism of action of the SSB interactome reveals it is the first OB-fold family of genome guardians in prokaryotes. Protein Sci 2021; 30:1757-1775. [PMID: 34089559 PMCID: PMC8376408 DOI: 10.1002/pro.4140] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 12/28/2022]
Abstract
The single-stranded DNA binding protein (SSB) is essential to all aspects of DNA metabolism in bacteria. This protein performs two distinct, but closely intertwined and indispensable functions in the cell. SSB binds to single-stranded DNA (ssDNA) and at least 20 partner proteins resulting in their regulation. These partners comprise a family of genome guardians known as the SSB interactome. Essential to interactome regulation is the linker/OB-fold network of interactions. This network of interactions forms when one or more PXXP motifs in the linker of SSB bind to an OB-fold in a partner, with interactome members involved in competitive binding between the linker and ssDNA to their OB-fold. Consequently, when linker-binding occurs to an OB-fold in an interactome partner, proteins are loaded onto the DNA. When linker/OB-fold interactions occur between SSB tetramers, cooperative ssDNA-binding results, producing a multi-tetrameric complex that rapidly protects the ssDNA. Within this SSB-ssDNA complex, there is an extensive and dynamic network of linker/OB-fold interactions that involves multiple tetramers bound contiguously along the ssDNA lattice. The dynamic behavior of these tetramers which includes binding mode changes, sliding as well as DNA wrapping/unwrapping events, are likely coupled to the formation and disruption of linker/OB-fold interactions. This behavior is essential to facilitating downstream DNA processing events. As OB-folds are critical to the essence of the linker/OB-fold network of interactions, and they are found in multiple interactome partners, the SSB interactome is classified as the first family of prokaryotic, oligosaccharide/oligonucleotide binding fold (OB-fold) genome guardians.
Collapse
MESH Headings
- Amino Acid Motifs
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Binding, Competitive
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- DNA, Single-Stranded/chemistry
- DNA, Single-Stranded/genetics
- DNA, Single-Stranded/metabolism
- DNA-Binding Proteins/chemistry
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression Regulation, Bacterial
- Gene Regulatory Networks
- Genome, Bacterial
- Klebsiella pneumoniae/chemistry
- Klebsiella pneumoniae/genetics
- Klebsiella pneumoniae/metabolism
- Models, Molecular
- Oligonucleotides/chemistry
- Oligonucleotides/metabolism
- Oligosaccharides/chemistry
- Oligosaccharides/metabolism
- Protein Binding
- Protein Conformation
- Protein Interaction Mapping
- Protein Multimerization
Collapse
Affiliation(s)
- Piero R. Bianco
- Department of Pharmaceutical Sciences, College of PharmacyUniversity of Nebraska Medical CenterOmahaNebraskaUSA
| |
Collapse
|
18
|
High-Throughput Screening to Identify Inhibitors of SSB-Protein Interactions. Methods Mol Biol 2021. [PMID: 33847955 DOI: 10.1007/978-1-0716-1290-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The bacterial single-stranded DNA-binding protein (SSB) uses an acidic C-terminal tail to interact with over a dozen proteins, acting as a genome maintenance hub. These SSB-protein interactions are essential, as mutations to the C-terminal tail that disrupt these interactions are lethal in Escherichia coli. While the roles of individual SSB-protein interactions have been dissected with mutational studies, small-molecule inhibitors of these interactions could serve as valuable research tools and have potential as novel antimicrobial agents. This chapter describes a high-throughput screening campaign used to identify inhibitors of SSB-protein interactions. A screen targeting the PriA-SSB interface from Klebsiella pneumoniae is presented as an example, but the methods may be adapted to target nearly any SSB interaction.
Collapse
|
19
|
Chédin F, Hartono SR, Sanz LA, Vanoosthuyse V. Best practices for the visualization, mapping, and manipulation of R-loops. EMBO J 2021; 40:e106394. [PMID: 33411340 PMCID: PMC7883053 DOI: 10.15252/embj.2020106394] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/25/2020] [Accepted: 11/10/2020] [Indexed: 01/12/2023] Open
Abstract
R-loops represent an abundant class of large non-B DNA structures in genomes. Even though they form transiently and at modest frequencies, interfering with R-loop formation or dissolution has significant impacts on genome stability. Addressing the mechanism(s) of R-loop-mediated genome destabilization requires a precise characterization of their distribution in genomes. A number of independent methods have been developed to visualize and map R-loops, but their results are at times discordant, leading to confusion. Here, we review the main existing methodologies for R-loop mapping and assess their limitations as well as the robustness of existing datasets. We offer a set of best practices to improve the reproducibility of maps, hoping that such guidelines could be useful for authors and referees alike. Finally, we propose a possible resolution for the apparent contradictions in R-loop mapping outcomes between antibody-based and RNase H1-based mapping approaches.
Collapse
Affiliation(s)
- Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome CenterUniversity of California, DavisDavisCAUSA
| | - Stella R Hartono
- Department of Molecular and Cellular Biology and Genome CenterUniversity of California, DavisDavisCAUSA
| | - Lionel A Sanz
- Department of Molecular and Cellular Biology and Genome CenterUniversity of California, DavisDavisCAUSA
| | - Vincent Vanoosthuyse
- Laboratoire de Biologie et Modélisation de la CelluleCNRSUMR 5239Univ LyonÉcole Normale Supérieure de LyonLyonFrance
| |
Collapse
|
20
|
Sutera VA, Weeks SJ, Dudenhausen EE, Baggett HBR, Shaw MC, Brand KA, Glass DJ, Bloom LB, Lovett ST. Alternative complexes formed by the Escherichia coli clamp loader accessory protein HolC (x) with replication protein HolD (ψ) and repair protein YoaA. DNA Repair (Amst) 2021; 100:103006. [PMID: 33582602 DOI: 10.1016/j.dnarep.2020.103006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 10/22/2022]
Abstract
Efficient and faithful replication of DNA is essential for all organisms. However, the replication fork frequently encounters barriers that need to be overcome to ensure cell survival and genetic stability. Cells must carefully balance and regulate replication vs. repair reactions. In Escherichia coli, the replisome consists of the DNA polymerase III holoenzyme, including DNA polymerase, proofreading exonuclease, processivity clamp and clamp loader, as well as a fork helicase, DnaB and primase, DnaG. We provide evidence here that one component of the clamp loader complex, HolC (or χ) plays a dual role via its ability to form 2 mutually exclusive complexes: one with HolD (or ψ) that recruits the clamp-loader and hence the DNA polymerase holoenzyme and another with helicase-like YoaA protein, a DNA-damage inducible repair protein. By yeast 2 hybrid analysis, we show that two residues of HolC, F64 and W57, at the interface in the structure with HolD, are required for interaction with HolD and for interaction with YoaA. Mutation of these residues does not interfere with HolC's interaction with single-strand DNA binding protein, SSB. In vivo, these mutations fail to complement the poor growth and sensitivity to azidothymidine, a chain-terminating replication inhibitor. In support of the notion that these are exclusive complexes, co-expression of HolC, HolD and YoaA, followed by pulldown of YoaA, yields a complex with HolC but not HolD. YoaA fails to pulldown HolC-F64A. We hypothesize that HolC, by binding with SSB, can recruit the DNA polymerase III holoenzyme through HolD, or an alternative repair complex with YoaA helicase.
Collapse
Affiliation(s)
- Vincent A Sutera
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, MS029, 415 South St., Waltham, MA, 02453, United States
| | - Savannah J Weeks
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, 32610-0245, United States
| | - Elizabeth E Dudenhausen
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, 32610-0245, United States
| | - Helen B Rappe Baggett
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, MS029, 415 South St., Waltham, MA, 02453, United States
| | - McKay C Shaw
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, MS029, 415 South St., Waltham, MA, 02453, United States
| | - Kirsten A Brand
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, MS029, 415 South St., Waltham, MA, 02453, United States
| | - David J Glass
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, MS029, 415 South St., Waltham, MA, 02453, United States
| | - Linda B Bloom
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, 32610-0245, United States
| | - Susan T Lovett
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, MS029, 415 South St., Waltham, MA, 02453, United States.
| |
Collapse
|
21
|
Mutational Analysis of Residues in PriA and PriC Affecting Their Ability To Interact with SSB in Escherichia coli K-12. J Bacteriol 2020; 202:JB.00404-20. [PMID: 32900829 DOI: 10.1128/jb.00404-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/01/2020] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli PriA and PriC recognize abandoned replication forks and direct reloading of the DnaB replicative helicase onto the lagging-strand template coated with single-stranded DNA-binding protein (SSB). Both PriA and PriC have been shown by biochemical and structural studies to physically interact with the C terminus of SSB. In vitro, these interactions trigger remodeling of the SSB on ssDNA. priA341(R697A) and priC351(R155A) negated the SSB remodeling reaction in vitro Plasmid-carried priC351(R155A) did not complement priC303::kan, and priA341(R697A) has not yet been tested for complementation. Here, we further studied the SSB-binding pockets of PriA and PriC by placing priA341(R697A), priA344(R697E), priA345(Q701E), and priC351(R155A) on the chromosome and characterizing the mutant strains. All three priA mutants behaved like the wild type. In a ΔpriB strain, the mutations caused modest increases in SOS expression, cell size, and defects in nucleoid partitioning (Par-). Overproduction of SSB partially suppressed these phenotypes for priA341(R697A) and priA344(R697E). The priC351(R155A) mutant behaved as expected: there was no phenotype in a single mutant, and there were severe growth defects when this mutation was combined with ΔpriB Analysis of the priBC mutant revealed two populations of cells: those with wild-type phenotypes and those that were extremely filamentous and Par- and had high SOS expression. We conclude that in vivo, priC351(R155A) identified an essential residue and function for PriC, that PriA R697 and Q701 are important only in the absence of PriB, and that this region of the protein may have a complicated relationship with SSB.IMPORTANCE Escherichia coli PriA and PriC recruit the replication machinery to a collapsed replication fork after it is repaired and needs to be restarted. In vitro studies suggest that the C terminus of SSB interacts with certain residues in PriA and PriC to recruit those proteins to the repaired fork, where they help remodel it for restart. Here, we placed those mutations on the chromosome and tested the effect of mutating these residues in vivo The priC mutation completely abolished function. The priA mutations had no effect by themselves. They did, however, display modest phenotypes in a priB-null strain. These phenotypes were partially suppressed by SSB overproduction. These studies give us further insight into the reactions needed for replication restart.
Collapse
|
22
|
González de Cózar JM, Carretero-Junquera M, Ciesielski GL, Miettinen SM, Varjosalo M, Kaguni LS, Dufour E, Jacobs HT. A second hybrid-binding domain modulates the activity of Drosophila ribonuclease H1. J Biochem 2020; 168:515-533. [PMID: 32589740 PMCID: PMC7657459 DOI: 10.1093/jb/mvaa067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/15/2020] [Indexed: 11/14/2022] Open
Abstract
In eukaryotes, ribonuclease H1 (RNase H1) is involved in the processing and removal of RNA/DNA hybrids in both nuclear and mitochondrial DNA. The enzyme comprises a C-terminal catalytic domain and an N-terminal hybrid-binding domain (HBD), separated by a linker of variable length, 115 amino acids in Drosophila melanogaster (Dm). Molecular modelling predicted this extended linker to fold into a structure similar to the conserved HBD. Based on a deletion series, both the catalytic domain and the conserved HBD were required for high-affinity binding to heteroduplex substrates, while loss of the novel HBD led to an ∼90% drop in Kcat with a decreased KM, and a large increase in the stability of the RNA/DNA hybrid-enzyme complex, supporting a bipartite-binding model in which the second HBD facilitates processivity. Shotgun proteomics following in vivo cross-linking identified single-stranded DNA-binding proteins from both nuclear and mitochondrial compartments, respectively RpA-70 and mtSSB, as prominent interaction partners of Dm RNase H1. However, we were not able to document direct and stable interactions with mtSSB when the proteins were co-overexpressed in S2 cells, and functional interactions between them in vitro were minor.
Collapse
Affiliation(s)
| | | | - Grzegorz L Ciesielski
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, Auburn University at Montgomery, Montgomery, AL 36117, USA
| | - Sini M Miettinen
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Laurie S Kaguni
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Eric Dufour
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| |
Collapse
|
23
|
Mehmood A, Naseer S, Ali A, Fatimah H, Rehman S, Kiani AK. Identification of novel vaccine candidates against carbapenem resistant Klebsiella pneumoniae: A systematic reverse proteomic approach. Comput Biol Chem 2020; 89:107380. [PMID: 32992120 DOI: 10.1016/j.compbiolchem.2020.107380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 08/09/2020] [Accepted: 09/18/2020] [Indexed: 11/18/2022]
Abstract
Klebsiella pneumoniae is declared as antibiotic resistant by WHO, with the critical urgency of developing novel antimicrobial therapeutics as drug resistance is the second most dangerous threat after terrorism. Besides many attempts still, there is no effective vaccine available against K. pneumoniae. By utilizing all the available proteomic data we prioritized the novel proteins ideal for vaccine development using bioinformatics tools and techniques. Among the huge data, eight proteins passed all the barriers and were considered ideal candidates for vaccine development. These include: copper silver efflux system outer membrane protein (CusC), outer membrane porin protein (OmpN), Fe++ enterobactin transporter substrate binding protein (fepB), zinc transporter substrate binding protein (ZnuA), ribonuclease HI, tellurite resistant methyltransferase (the B), and two uncharacterized hypothetical proteins (WP_002918223 and WP_002892366). These proteins were also subjected to epitope analysis and were found best for developing subunit vaccine against K. pneumoniae. The study shows that the potential vaccine targets are sufficiently efficient being virulent, of outer membranous origin and can be proposed for the DNA third-generation vaccines development that would help to cope up infections caused by multidrug-resistant K. pneumoniae.
Collapse
Affiliation(s)
- Asim Mehmood
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan
| | - Samar Naseer
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan.
| | - Amjad Ali
- Department of Industrial Biotechnology, Atta Ur Rahman School of Applied Biosciences (ASAB), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Hina Fatimah
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan
| | - Shazia Rehman
- Department of Botany, Rawalpindi Women University, Rawalpindi, Pakistan
| | - Aysha Karim Kiani
- Department of Biology and Environmental Science, Faculty of Sciences, Allama Iqbal Open University, Islamabad, Pakistan
| |
Collapse
|
24
|
Dueva R, Iliakis G. Replication protein A: a multifunctional protein with roles in DNA replication, repair and beyond. NAR Cancer 2020; 2:zcaa022. [PMID: 34316690 PMCID: PMC8210275 DOI: 10.1093/narcan/zcaa022] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 02/07/2023] Open
Abstract
Single-stranded DNA (ssDNA) forms continuously during DNA replication and is an important intermediate during recombination-mediated repair of damaged DNA. Replication protein A (RPA) is the major eukaryotic ssDNA-binding protein. As such, RPA protects the transiently formed ssDNA from nucleolytic degradation and serves as a physical platform for the recruitment of DNA damage response factors. Prominent and well-studied RPA-interacting partners are the tumor suppressor protein p53, the RAD51 recombinase and the ATR-interacting proteins ATRIP and ETAA1. RPA interactions are also documented with the helicases BLM, WRN and SMARCAL1/HARP, as well as the nucleotide excision repair proteins XPA, XPG and XPF–ERCC1. Besides its well-studied roles in DNA replication (restart) and repair, accumulating evidence shows that RPA is engaged in DNA activities in a broader biological context, including nucleosome assembly on nascent chromatin, regulation of gene expression, telomere maintenance and numerous other aspects of nucleic acid metabolism. In addition, novel RPA inhibitors show promising effects in cancer treatment, as single agents or in combination with chemotherapeutics. Since the biochemical properties of RPA and its roles in DNA repair have been extensively reviewed, here we focus on recent discoveries describing several non-canonical functions.
Collapse
Affiliation(s)
- Rositsa Dueva
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
| |
Collapse
|
25
|
Wolak C, Ma HJ, Soubry N, Sandler SJ, Reyes-Lamothe R, Keck JL. Interaction with single-stranded DNA-binding protein localizes ribonuclease HI to DNA replication forks and facilitates R-loop removal. Mol Microbiol 2020; 114:495-509. [PMID: 32426857 PMCID: PMC7934204 DOI: 10.1111/mmi.14529] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/30/2020] [Accepted: 05/09/2020] [Indexed: 01/06/2023]
Abstract
DNA replication complexes (replisomes) routinely encounter proteins and unusual nucleic acid structures that can impede their progress. Barriers can include transcription complexes and R-loops that form when RNA hybridizes with complementary DNA templates behind RNA polymerases. Cells encode several RNA polymerase and R-loop clearance mechanisms to limit replisome exposure to these potential obstructions. One such mechanism is hydrolysis of R-loops by ribonuclease HI (RNase HI). Here, we examine the cellular role of the interaction between Escherichia coli RNase HI and the single-stranded DNA-binding protein (SSB) in this process. Interaction with SSB localizes RNase HI foci to DNA replication sites. Mutation of rnhA to encode an RNase HI variant that cannot interact with SSB but that maintains enzymatic activity (rnhAK60E) eliminates RNase HI foci. The mutation also produces a media-dependent slow-growth phenotype and an activated DNA damage response in cells lacking Rep helicase, which is an enzyme that disrupts stalled transcription complexes. RNA polymerase variants that are thought to increase or decrease R-loop accumulation enhance or suppress, respectively, the growth phenotype of rnhAK60E rep::kan strains. These results identify a cellular role for the RNase HI/SSB interaction in helping to clear R-loops that block DNA replication.
Collapse
Affiliation(s)
- Christine Wolak
- Department of Biomolecular Chemistry, 420 Henry Mall, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| | - Hui Jun Ma
- Department of Biology, McGill University, 3649 Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - Nicolas Soubry
- Department of Biology, McGill University, 3649 Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - Steven J. Sandler
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Rodrigo Reyes-Lamothe
- Department of Biology, McGill University, 3649 Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - James L. Keck
- Department of Biomolecular Chemistry, 420 Henry Mall, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| |
Collapse
|
26
|
Dubiel K, Henry C, Spenkelink LM, Kozlov AG, Wood EA, Jergic S, Dixon NE, van Oijen AM, Cox MM, Lohman TM, Sandler SJ, Keck JL. Development of a single-stranded DNA-binding protein fluorescent fusion toolbox. Nucleic Acids Res 2020; 48:6053-6067. [PMID: 32374866 PMCID: PMC7293020 DOI: 10.1093/nar/gkaa320] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 04/15/2020] [Accepted: 05/04/2020] [Indexed: 01/13/2023] Open
Abstract
Bacterial single-stranded DNA-binding proteins (SSBs) bind single-stranded DNA and help to recruit heterologous proteins to their sites of action. SSBs perform these essential functions through a modular structural architecture: the N-terminal domain comprises a DNA binding/tetramerization element whereas the C-terminus forms an intrinsically disordered linker (IDL) capped by a protein-interacting SSB-Ct motif. Here we examine the activities of SSB-IDL fusion proteins in which fluorescent domains are inserted within the IDL of Escherichia coli SSB. The SSB-IDL fusions maintain DNA and protein binding activities in vitro, although cooperative DNA binding is impaired. In contrast, an SSB variant with a fluorescent protein attached directly to the C-terminus that is similar to fusions used in previous studies displayed dysfunctional protein interaction activity. The SSB-IDL fusions are readily visualized in single-molecule DNA replication reactions. Escherichia coli strains in which wildtype SSB is replaced by SSB-IDL fusions are viable and display normal growth rates and fitness. The SSB-IDL fusions form detectible SSB foci in cells with frequencies mirroring previously examined fluorescent DNA replication fusion proteins. Cells expressing SSB-IDL fusions are sensitized to some DNA damaging agents. The results highlight the utility of SSB-IDL fusions for biochemical and cellular studies of genome maintenance reactions.
Collapse
Affiliation(s)
- Katarzyna Dubiel
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Camille Henry
- Department of Biochemistry, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Lisanne M Spenkelink
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
| | - Alexander G Kozlov
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Elizabeth A Wood
- Department of Biochemistry, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Slobodan Jergic
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
| | - Nicholas E Dixon
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
| | - Antoine M van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
| | - Michael M Cox
- Department of Biochemistry, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Timothy M Lohman
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Steven J Sandler
- Department of Microbiology, University of Massachusetts at Amherst, Amherst, MA 01003, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| |
Collapse
|
27
|
Xing KY, Peng J, Shan S, Liu DF, Huang YN, Lai WH. Green Enzyme-Linked Immunosorbent Assay Based on the Single-Stranded Binding Protein-Assisted Aptamer for the Detection of Mycotoxin. Anal Chem 2020; 92:8422-8426. [PMID: 32403920 DOI: 10.1021/acs.analchem.0c01073] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this work, a green enzyme-linked immunosorbent assay (ELISA) based on the single-stranded binding protein (SSB)-assisted aptamer was designed for biosensing applications. Combined with the biotin-streptavidin (SA) system and the high catalytic activity of horseradish peroxidase (HRP), this SSB-assisted aptamer sensor was applied for the detection of aflatoxin B1, ochratoxin A, and zearalenone. In this novel ELISA, mycotoxin-protein conjugations were replaced by SSB to avoid the hazard of mycotoxin, whereas antibodies were replaced by aptamer to avoid the complex and tedious preparation of antibodies. In the absence of target mycotoxins, SSB can bind the aptamer-biotin specifically. Detection was performed using the strong combination of biotin and SA after adding SA-HRP and substrate/chromogen solution, thereby resulting in a strong yellow color signal. In the presence of target mycotoxins, the aptamer-biotin cannot bind to the SSB, thereby leading to a weak yellow color signal. Under optimal conditions, the designed method was successfully applied for the determination of real sample and exhibited high specificity and low limits of detection in corn (112 ng L-1 for aflatoxin B1, 319 ng L-1 for ochratoxin A, and 377 ng L-1 for zearalenone). The green ELISA may also be extended to the detection of other biohazardous targets by changing the aptamer.
Collapse
Affiliation(s)
- Ke-Yu Xing
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Juan Peng
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Shan Shan
- College of life sciences, Jiangxi Normal University, Nanchang, 330022, China
| | - Dao-Feng Liu
- Jiangxi Province Center for Disease Control and Prevention, Nanchang, 330029, China
| | - Yi-Na Huang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Wei-Hua Lai
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| |
Collapse
|
28
|
Ding W, Tan HY, Zhang JX, Wilczek LA, Hsieh KR, Mulkin JA, Bianco PR. The mechanism of Single strand binding protein-RecG binding: Implications for SSB interactome function. Protein Sci 2020; 29:1211-1227. [PMID: 32196797 PMCID: PMC7184773 DOI: 10.1002/pro.3855] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/11/2020] [Accepted: 03/13/2020] [Indexed: 01/10/2023]
Abstract
The Escherichia coli single-strand DNA binding protein (SSB) is essential to viability where it functions to regulate SSB interactome function. Here it binds to single-stranded DNA and to target proteins that comprise the interactome. The region of SSB that links these two essential protein functions is the intrinsically disordered linker. Key to linker function is the presence of three, conserved PXXP motifs that mediate binding to oligosaccharide-oligonucleotide binding folds (OB-fold) present in SSB and its interactome partners. Not surprisingly, partner OB-fold deletions eliminate SSB binding. Furthermore, single point mutations in either the PXXP motifs or, in the RecG OB-fold, obliterate SSB binding. The data also demonstrate that, and in contrast to the view currently held in the field, the C-terminal acidic tip of SSB is not required for interactome partner binding. Instead, we propose the tip has two roles. First, and consistent with the proposal of Dixon, to regulate the structure of the C-terminal domain in a biologically active conformation that prevents linkers from binding to SSB OB-folds until this interaction is required. Second, as a secondary binding domain. Finally, as OB-folds are present in SSB and many of its partners, we present the SSB interactome as the first family of OB-fold genome guardians identified in prokaryotes.
Collapse
Affiliation(s)
- Wenfei Ding
- Center for Single Molecule BiophysicsUniversity at BuffaloBuffaloNew YorkUnited States
- Department of BiochemistryUniversity at BuffaloBuffaloNew YorkUnited States
| | - Hui Yin Tan
- Center for Single Molecule BiophysicsUniversity at BuffaloBuffaloNew YorkUnited States
- Present address:
Department of Chemistry and BiochemistryUniversity of Notre DameSouth BendIndianaUnited States
| | - Jia Xiang Zhang
- Department of BiochemistryUniversity at BuffaloBuffaloNew YorkUnited States
| | - Luke A. Wilczek
- Center for Single Molecule BiophysicsUniversity at BuffaloBuffaloNew YorkUnited States
- Department of BiochemistryUniversity at BuffaloBuffaloNew YorkUnited States
- Present address:
Department of ChemistryBrown UniversityProvidenceRhode IslandUnited States
| | - Karin R. Hsieh
- Center for Single Molecule BiophysicsUniversity at BuffaloBuffaloNew YorkUnited States
| | - Jeffrey A. Mulkin
- Center for Single Molecule BiophysicsUniversity at BuffaloBuffaloNew YorkUnited States
| | - Piero R. Bianco
- Center for Single Molecule BiophysicsUniversity at BuffaloBuffaloNew YorkUnited States
- Department of BiochemistryUniversity at BuffaloBuffaloNew YorkUnited States
| |
Collapse
|
29
|
Drolet M, Brochu J. R-loop-dependent replication and genomic instability in bacteria. DNA Repair (Amst) 2019; 84:102693. [DOI: 10.1016/j.dnarep.2019.102693] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/14/2019] [Accepted: 08/20/2019] [Indexed: 12/20/2022]
|
30
|
Lockhart A, Pires VB, Bento F, Kellner V, Luke-Glaser S, Yakoub G, Ulrich HD, Luke B. RNase H1 and H2 Are Differentially Regulated to Process RNA-DNA Hybrids. Cell Rep 2019; 29:2890-2900.e5. [DOI: 10.1016/j.celrep.2019.10.108] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/10/2019] [Accepted: 10/28/2019] [Indexed: 10/25/2022] Open
|
31
|
Wang J, Zhao F, Sun H, Wang Q, Zhang C, Liu W, Zou L, Pan Q, Ren H. Isolation and characterization of the Staphylococcus aureus bacteriophage vB_SauS_SA2. AIMS Microbiol 2019; 5:285-307. [PMID: 31663062 PMCID: PMC6787349 DOI: 10.3934/microbiol.2019.3.285] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 09/25/2019] [Indexed: 12/28/2022] Open
Abstract
A novel bacteriophage vB_SauS_SA2 (hereafter designated SA2) that infects Staphylococcus aureus was isolated. At a multiplicity of infection (MOI) of 0.1, phage SA2 had a latent period of about 10 min with a burst size of 293 PFUs/infected cell (PFU, plaque forming unit). Phage SA2 had a double-stranded DNA genome with a length of 89,055 bp and a G + C content of 31.9%. The genome contained 130 open reading frames (ORFs), 28 of which had assigned functions, and 18 were unique. One tRNA gene (tRNAAsn) was discovered, and no virulence genes were identified. Its genome showed very low similarity with phage genomes deposited in public databases (75% nucleotide identity and 7% query coverage). The unique characteristics of phage SA2 led to the proposal of a new Siphoviridae genus named ‘SA2likevirus’.
Collapse
Affiliation(s)
- Jia Wang
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| | - Feiyang Zhao
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| | - Huzhi Sun
- Qingdao Phagepharm Bio-tech Co, Ltd, Shandong 266109, China
| | - Qian Wang
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| | - Can Zhang
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| | - Wenhua Liu
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| | - Ling Zou
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| | - Qiang Pan
- Qingdao Phagepharm Bio-tech Co, Ltd, Shandong 266109, China
| | - Huiying Ren
- Qingdao Agricultural University, College of Veterinary Medicine, Shandong 266109, China
| |
Collapse
|
32
|
Caldwell BJ, Zakharova E, Filsinger GT, Wannier TM, Hempfling JP, Chun-Der L, Pei D, Church GM, Bell CE. Crystal structure of the Redβ C-terminal domain in complex with λ Exonuclease reveals an unexpected homology with λ Orf and an interaction with Escherichia coli single stranded DNA binding protein. Nucleic Acids Res 2019; 47:1950-1963. [PMID: 30624736 PMCID: PMC6393309 DOI: 10.1093/nar/gky1309] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 12/18/2018] [Accepted: 12/23/2018] [Indexed: 02/06/2023] Open
Abstract
Bacteriophage λ encodes a DNA recombination system that includes a 5'-3' exonuclease (λ Exo) and a single strand annealing protein (Redβ). The two proteins form a complex that is thought to mediate loading of Redβ directly onto the single-stranded 3'-overhang generated by λ Exo. Here, we present a 2.3 Å crystal structure of the λ Exo trimer bound to three copies of the Redβ C-terminal domain (CTD). Mutation of residues at the hydrophobic core of the interface disrupts complex formation in vitro and impairs recombination in vivo. The Redβ CTD forms a three-helix bundle with unexpected structural homology to phage λ Orf, a protein that binds to E. coli single-stranded DNA binding protein (SSB) to function as a recombination mediator. Based on this relationship, we found that Redβ binds to full-length SSB, and to a peptide corresponding to its nine C-terminal residues, in an interaction that requires the CTD. These results suggest a dual role of the CTD, first in binding to λ Exo to facilitate loading of Redβ directly onto the initial single-stranded DNA (ssDNA) at a 3'-overhang, and second in binding to SSB to facilitate annealing of the overhang to SSB-coated ssDNA at the replication fork.
Collapse
Affiliation(s)
- Brian J Caldwell
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH 43210, USA
| | - Ekaterina Zakharova
- Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH 43210, USA
| | - Gabriel T Filsinger
- Department of Systems Biology, Harvard Medical School, Cambridge, MA 02138, USA
| | - Timothy M Wannier
- Department of Genetics, Harvard Medical School, Cambridge, MA 02138, USA
| | - Jordan P Hempfling
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Lee Chun-Der
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Dehua Pei
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - George M Church
- Department of Genetics, Harvard Medical School, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
| | - Charles E Bell
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| |
Collapse
|
33
|
Hyjek M, Figiel M, Nowotny M. RNases H: Structure and mechanism. DNA Repair (Amst) 2019; 84:102672. [PMID: 31371183 DOI: 10.1016/j.dnarep.2019.102672] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/05/2019] [Accepted: 07/12/2019] [Indexed: 12/11/2022]
Abstract
RNases H are a family of endonucleases that hydrolyze RNA residues in various nucleic acids. These enzymes are present in all branches of life, and their counterpart domains are also found in reverse transcriptases (RTs) from retroviruses and retroelements. RNases H are divided into two main classes (RNases H1 and H2 or type 1 and type 2 enzymes) with common structural features of the catalytic domain but different range of substrates for enzymatic cleavage. Additionally, a third class is found in some Archaea and bacteria. Besides distinct cellular functions specific for each type of RNases H, this family of proteins is generally involved in the maintenance of genome stability with overlapping and cooperative role in removal of R-loops thus preventing their accumulation. Extensive biochemical and structural studies of RNases H provided not only a comprehensive and complete picture of their mechanism but also revealed key basic principles of nucleic acid recognition and processing. RNase H1 is present in prokaryotes and eukaryotes and cleaves RNA in RNA/DNA hybrids. Its main function is hybrid removal, notably in the context of R-loops. RNase H2, which is also present in all branches of life, can play a similar role but it also has a specialized function in the cleavage of single ribonucleotides embedded in the DNA. RNase H3 is present in Archaea and bacteria and is closely related to RNase H2 in sequence and structure but has RNase H1-like biochemical properties. This review summarizes the mechanisms of substrate recognition and enzymatic cleavage by different classes of RNases H with particular insights into structural features of nucleic acid binding, specificity towards RNA and/or DNA strands and catalysis.
Collapse
Affiliation(s)
- Malwina Hyjek
- ProBiostructures, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw, 02-109, Poland.
| | - Małgorzata Figiel
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw, 02-109, Poland.
| | - Marcin Nowotny
- ProBiostructures, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw, 02-109, Poland; Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Trojdena 4, Warsaw, 02-109, Poland.
| |
Collapse
|
34
|
Abstract
Bacteria frequently encounter low concentrations of antibiotics. Active antibiotics are commonly detected in soil and water at concentrations much below lethal concentration. Although sub-MICs of antibiotics do not kill bacteria, they can have a major impact on bacterial populations by contributing to the development of antibiotic resistance through mutations in originally sensitive bacteria or acquisition of DNA from resistant bacteria. It was shown that concentrations as low as 100-fold below the MIC can actually lead to the selection of antibiotic-resistant cells. We seek to understand how bacterial cells react to such antibiotic concentrations using E. coli, the Gram-negative bacterial paradigm, and V. cholerae, the causative agent of cholera. Our findings shed light on the processes triggered at the DNA level by antibiotics targeting translation, how damage occurs, and what the bacterial strategies are to respond to such DNA damage. We have previously identified Vibrio cholerae mutants in which the stress response to subinhibitory concentrations of aminoglycoside is altered. One gene identified, VC1636, encodes a putative DNA/RNA helicase, recently named RadD in Escherichia coli. Here we combined extensive genetic characterization and high-throughput approaches in order to identify partners and molecular mechanisms involving RadD. We show that double-strand DNA breaks (DSBs) are formed upon subinhibitory tobramycin treatment in the absence of radD and recBCD and that formation of these DSBs can be overcome by RNase H1 overexpression. Loss of RNase H1, or of the transcription-translation coupling factor EF-P, is lethal in the radD deletion mutant. We propose that R-loops are formed upon sublethal aminoglycoside treatment, leading to the formation of DSBs that can be repaired by the RecBCD homologous recombination pathway, and that RadD counteracts such R-loop accumulation. We discuss how R-loops that can occur upon translation-transcription uncoupling could be the link between tobramycin treatment and DNA break formation.
Collapse
|
35
|
Bechhofer DH, Deutscher MP. Bacterial ribonucleases and their roles in RNA metabolism. Crit Rev Biochem Mol Biol 2019; 54:242-300. [PMID: 31464530 PMCID: PMC6776250 DOI: 10.1080/10409238.2019.1651816] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/22/2019] [Accepted: 07/31/2019] [Indexed: 12/16/2022]
Abstract
Ribonucleases (RNases) are mediators in most reactions of RNA metabolism. In recent years, there has been a surge of new information about RNases and the roles they play in cell physiology. In this review, a detailed description of bacterial RNases is presented, focusing primarily on those from Escherichia coli and Bacillus subtilis, the model Gram-negative and Gram-positive organisms, from which most of our current knowledge has been derived. Information from other organisms is also included, where relevant. In an extensive catalog of the known bacterial RNases, their structure, mechanism of action, physiological roles, genetics, and possible regulation are described. The RNase complement of E. coli and B. subtilis is compared, emphasizing the similarities, but especially the differences, between the two. Included are figures showing the three major RNA metabolic pathways in E. coli and B. subtilis and highlighting specific steps in each of the pathways catalyzed by the different RNases. This compilation of the currently available knowledge about bacterial RNases will be a useful tool for workers in the RNA field and for others interested in learning about this area.
Collapse
Affiliation(s)
- David H. Bechhofer
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Murray P. Deutscher
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
36
|
Randall JR, Nye TM, Wozniak KJ, Simmons LA. RNase HIII Is Important for Okazaki Fragment Processing in Bacillus subtilis. J Bacteriol 2019; 201:e00686-18. [PMID: 30670546 PMCID: PMC6416905 DOI: 10.1128/jb.00686-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/18/2019] [Indexed: 01/15/2023] Open
Abstract
RNA-DNA hybrids are common in chromosomal DNA. Persistent RNA-DNA hybrids result in replication fork stress, DNA breaks, and neurological disorders in humans. During replication, Okazaki fragment synthesis relies on frequent RNA primer placement, providing one of the most prominent forms of covalent RNA-DNA strands in vivo The mechanism of Okazaki fragment maturation, which involves RNA removal and subsequent DNA replacement, in bacteria lacking RNase HI remains unclear. In this work, we reconstituted repair of a linear model Okazaki fragment in vitro using purified recombinant enzymes from Bacillus subtilis We showed that RNase HII and HIII are capable of incision on Okazaki fragments in vitro and that both enzymes show mild stimulation by single-stranded DNA binding protein (SSB). We also showed that RNase HIII and DNA polymerase I provide the primary pathway for Okazaki fragment maturation in vitro Furthermore, we found that YpcP is a 5' to 3' nuclease that can act on a wide variety of RNA- and DNA-containing substrates and exhibits preference for degrading RNA in model Okazaki fragments. Together, our data showed that RNase HIII and DNA polymerase I provide the primary pathway for Okazaki fragment maturation, whereas YpcP also contributes to the removal of RNA from an Okazaki fragment in vitroIMPORTANCE All cells are required to resolve the different types of RNA-DNA hybrids that form in vivo When RNA-DNA hybrids persist, cells experience an increase in mutation rate and problems with DNA replication. Okazaki fragment synthesis on the lagging strand requires an RNA primer to begin synthesis of each fragment. The mechanism of RNA removal from Okazaki fragments remains unknown in bacteria that lack RNase HI. We examined Okazaki fragment processing in vitro and found that RNase HIII in conjunction with DNA polymerase I represent the most efficient repair pathway. We also assessed the contribution of YpcP and found that YpcP is a 5' to 3' exonuclease that prefers RNA substrates with activity on Okazaki and flap substrates in vitro.
Collapse
Affiliation(s)
- Justin R Randall
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Taylor M Nye
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine J Wozniak
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
37
|
Abstract
Most proteins associate with other proteins to function, forming complexes that are central to almost all physiological processes. Determining the structures of these complexes and understanding how they associate are problems of fundamental importance. Using long-timescale molecular dynamics simulations, some performed using a new enhanced sampling method, we observed spontaneous association and dissociation of five protein–protein systems to and from their experimentally determined native complexes. By analyzing the simulations of these five systems, which include members of diverse structural and functional classes, we are able to draw general mechanistic conclusions about protein association. Despite the biological importance of protein–protein complexes, determining their structures and association mechanisms remains an outstanding challenge. Here, we report the results of atomic-level simulations in which we observed five protein–protein pairs repeatedly associate to, and dissociate from, their experimentally determined native complexes using a molecular dynamics (MD)–based sampling approach that does not make use of any prior structural information about the complexes. To study association mechanisms, we performed additional, conventional MD simulations, in which we observed numerous spontaneous association events. A shared feature of native association for these five structurally and functionally diverse protein systems was that if the proteins made contact far from the native interface, the native state was reached by dissociation and eventual reassociation near the native interface, rather than by extensive interfacial exploration while the proteins remained in contact. At the transition state (the conformational ensemble from which association to the native complex and dissociation are equally likely), the protein–protein interfaces were still highly hydrated, and no more than 20% of native contacts had formed.
Collapse
|
38
|
González de Cózar JM, Gerards M, Teeri E, George J, Dufour E, Jacobs HT, Jõers P. RNase H1 promotes replication fork progression through oppositely transcribed regions of Drosophila mitochondrial DNA. J Biol Chem 2019; 294:4331-4344. [PMID: 30635398 PMCID: PMC6433063 DOI: 10.1074/jbc.ra118.007015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/09/2019] [Indexed: 11/12/2022] Open
Abstract
Mitochondrial DNA (mtDNA) replication uses a simple core machinery similar to those of bacterial viruses and plasmids, but its components are challenging to unravel. Here, we found that, as in mammals, the single Drosophila gene for RNase H1 (rnh1) has alternative translational start sites, resulting in two polypeptides, targeted to either mitochondria or the nucleus. RNAi-mediated rnh1 knockdown did not influence growth or viability of S2 cells, but compromised mtDNA integrity and copy number. rnh1 knockdown in intact flies also produced a phenotype of impaired mitochondrial function, characterized by respiratory chain deficiency, locomotor dysfunction, and decreased lifespan. Its overexpression in S2 cells resulted in cell lethality after 5–9 days, attributable to the nuclearly localized isoform. rnh1 knockdown and overexpression produced opposite effects on mtDNA replication intermediates. The most pronounced effects were seen in genome regions beyond the major replication pauses where the replication fork needs to progress through a gene cluster that is transcribed in the opposite direction. RNase H1 deficiency led to an accumulation of replication intermediates in these zones, abundant mtDNA molecules joined by four-way junctions, and species consistent with fork regression from the origin. These findings indicate replication stalling due to the presence of unprocessed RNA/DNA heteroduplexes, potentially leading to the degradation of collapsed forks or to replication restart by a mechanism involving strand invasion. Both mitochondrial RNA and DNA syntheses were affected by rnh1 knockdown, suggesting that RNase H1 also plays a role in integrating or coregulating these processes in Drosophila mitochondria.
Collapse
Affiliation(s)
- Jose M González de Cózar
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Mike Gerards
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Eveliina Teeri
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Jack George
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Eric Dufour
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland, .,Institute of Biotechnology, FI-00014 University of Helsinki, Finland, and
| | - Priit Jõers
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland.,Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| |
Collapse
|
39
|
Dubiel K, Myers AR, Kozlov AG, Yang O, Zhang J, Ha T, Lohman TM, Keck JL. Structural Mechanisms of Cooperative DNA Binding by Bacterial Single-Stranded DNA-Binding Proteins. J Mol Biol 2018; 431:178-195. [PMID: 30472092 DOI: 10.1016/j.jmb.2018.11.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/07/2018] [Accepted: 11/14/2018] [Indexed: 12/19/2022]
Abstract
Bacteria encode homooligomeric single-stranded (ss) DNA-binding proteins (SSBs) that coat and protect ssDNA intermediates formed during genome maintenance reactions. The prototypical Escherichia coli SSB tetramer can bind ssDNA using multiple modes that differ by the number of bases bound per tetramer and the magnitude of the binding cooperativity. Our understanding of the mechanisms underlying cooperative ssDNA binding by SSBs has been hampered by the limited amount of structural information available for interfaces that link adjacent SSB proteins on ssDNA. Here we present a crystal structure of Bacillus subtilis SsbA bound to ssDNA. The structure resolves SsbA tetramers joined together by a ssDNA "bridge" and identifies an interface, termed the "bridge interface," that links adjacent SSB tetramers through an evolutionarily conserved surface near the ssDNA-binding site. E. coli SSB variants with altered bridge interface residues bind ssDNA with reduced cooperativity and with an altered distribution of DNA binding modes. These variants are also more readily displaced from ssDNA by RecA than wild-type SSB. In spite of these biochemical differences, each variant is able to complement deletion of the ssb gene in E. coli. Together our data suggest a model in which the bridge interface contributes to cooperative ssDNA binding and SSB function but that destabilization of the bridge interface is tolerated in cells.
Collapse
Affiliation(s)
- Katarzyna Dubiel
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Angela R Myers
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Alexander G Kozlov
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Olivia Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Jichuan Zhang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, 725 N. Wolfe Street, Baltimore, MD 21205, USA; Department of Biophysics, Johns Hopkins University and Howard Hughes Medical Institute, 725 N. Wolfe Street, Baltimore, MD 21205, USA; Department of Biomedical Engineering, Johns Hopkins University and Howard Hughes Medical Institute, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Timothy M Lohman
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA.
| |
Collapse
|
40
|
Topoisomerases I and III inhibit R-loop formation to prevent unregulated replication in the chromosomal Ter region of Escherichia coli. PLoS Genet 2018; 14:e1007668. [PMID: 30222737 PMCID: PMC6160223 DOI: 10.1371/journal.pgen.1007668] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/27/2018] [Accepted: 08/29/2018] [Indexed: 02/07/2023] Open
Abstract
Type 1A topoisomerases (topos) are the only ubiquitous topos. E. coli has two type 1A topos, topo I (topA) and topo III (topB). Topo I relaxes negative supercoiling in part to inhibit R-loop formation. To grow, topA mutants acquire compensatory mutations, base substitutions in gyrA or gyrB (gyrase) or amplifications of a DNA region including parC and parE (topo IV). topB mutants grow normally and topo III binds tightly to single-stranded DNA. What functions topo I and III share in vivo and how cells lacking these important enzymes can survive is unclear. Previously, a gyrB(Ts) compensatory mutation was used to construct topA topB null mutants. These mutants form very long filaments and accumulate diffuse DNA, phenotypes that appears to be related to replication from R-loops. Here, next generation sequencing and qPCR for marker frequency analysis were used to further define the functions of type 1A topos. The results reveal the presence of a RNase HI-sensitive origin of replication in the terminus (Ter) region of the chromosome that is more active in topA topB cells than in topA and rnhA (RNase HI) null cells. The S9.6 antibodies specific to DNA:RNA hybrids were used in dot-blot experiments to show the accumulation of R-loops in rnhA, topA and topA topB null cells. Moreover topA topB gyrB(Ts) strains, but not a topA gyrB(Ts) strain, were found to carry a parC parE amplification. When a topA gyrB(Ts) mutant carried a plasmid producing topo IV, topB null transductants did not have parC parE amplifications. Altogether, the data indicate that in E. coli type 1A topos are required to inhibit R-loop formation/accumulation mostly to prevent unregulated replication in Ter, and that they are essential to prevent excess negative supercoiling and its detrimental effects on cell growth and survival. DNA topoisomerases are nicking closing enzymes with strand passage activity that solves the topological problems inherent to the double-helical structure of DNA. Topos of the type 1A family are the only ubiquitous topos. They are classified in two subfamilies, topo I and topo III respectively found in bacteria only and in organisms from the three domains of life. The prototype enzymes of these two subfamilies are topo I and topo III from Escherichia coli. Recent data suggest that duplications leading to topo I and III subfamilies occurred in the Last Common Universal Ancestor of the three domains of life. In this context, our finding reported here that both E. coli topo I and III control R-loop formation/accumulation, mostly to inhibit unregulated replication, may suggest that R-loops have been a problem early in the evolution of life. Furthermore, our data show that E. coli cells can survive in the absence of type 1A topos, owing to the surproduction of topo IV that can relax excess negative supercoiling and prevent R-loop formation. Thus, our results strongly suggest that a major function of type 1A topos is to control R-loop formation to preserve the integrity of the genome.
Collapse
|
41
|
Antony E, Lohman TM. Dynamics of E. coli single stranded DNA binding (SSB) protein-DNA complexes. Semin Cell Dev Biol 2018; 86:102-111. [PMID: 29588158 DOI: 10.1016/j.semcdb.2018.03.017] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/22/2018] [Accepted: 03/23/2018] [Indexed: 01/25/2023]
Abstract
Single stranded DNA binding proteins (SSB) are essential to the cell as they stabilize transiently open single stranded DNA (ssDNA) intermediates, recruit appropriate DNA metabolism proteins, and coordinate fundamental processes such as replication, repair and recombination. Escherichia coli single stranded DNA binding protein (EcSSB) has long served as the prototype for the study of SSB function. The structure, functions, and DNA binding properties of EcSSB are well established: The protein is a stable homotetramer with each subunit possessing an N-terminal DNA binding core, a C-terminal protein-protein interaction tail, and an intervening intrinsically disordered linker (IDL). EcSSB wraps ssDNA in multiple DNA binding modes and can diffuse along DNA to remove secondary structures and remodel other protein-DNA complexes. This review provides an update on these features based on recent findings, with special emphasis on the functional and mechanistic relevance of the IDL and DNA binding modes.
Collapse
Affiliation(s)
- Edwin Antony
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA.
| | - Timothy M Lohman
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
42
|
Voter AF, Killoran MP, Ananiev GE, Wildman SA, Hoffmann FM, Keck JL. A High-Throughput Screening Strategy to Identify Inhibitors of SSB Protein-Protein Interactions in an Academic Screening Facility. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2018; 23:94-101. [PMID: 28570838 PMCID: PMC5667550 DOI: 10.1177/2472555217712001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antibiotic-resistant bacterial infections are increasingly prevalent worldwide, and there is an urgent need for novel classes of antibiotics capable of overcoming existing resistance mechanisms. One potential antibiotic target is the bacterial single-stranded DNA binding protein (SSB), which serves as a hub for DNA repair, recombination, and replication. Eight highly conserved residues at the C-terminus of SSB use direct protein-protein interactions (PPIs) to recruit more than a dozen important genome maintenance proteins to single-stranded DNA. Mutations that disrupt PPIs with the C-terminal tail of SSB are lethal, suggesting that small-molecule inhibitors of these critical SSB PPIs could be effective antibacterial agents. As a first step toward implementing this strategy, we have developed orthogonal high-throughput screening assays to identify small-molecule inhibitors of the Klebsiella pneumonia SSB-PriA interaction. Hits were identified from an initial screen of 72,474 compounds using an AlphaScreen (AS) primary screen, and their activity was subsequently confirmed in an orthogonal fluorescence polarization (FP) assay. As an additional control, an FP assay targeted against an unrelated eukaryotic PPI was used to confirm specificity for the SSB-PriA interaction. Nine potent and selective inhibitors produced concentration-response curves with IC50 values of <40 μM, and two compounds were observed to directly bind to PriA, demonstrating the success of this screen strategy.
Collapse
Affiliation(s)
- Andrew F. Voter
- Department of Biomolecular Chemistry, Room 1135 Biochemistry Building, 420 Henry Mall, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706. Tel: 608-263-1954. Fax: 608-262-5253.
| | - Michael P. Killoran
- Department of Biomolecular Chemistry, Room 1135 Biochemistry Building, 420 Henry Mall, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706. Tel: 608-263-1954. Fax: 608-262-5253.
- Department of Biomolecular Chemistry, Room 1135 Biochemistry Building, 420 Henry Mall, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706. Current contact: Promega Corporation, Madison, Wisconsin 53711, United States. Tel: 608-443-3116.
| | - Gene E. Ananiev
- UW Carbone Cancer Center Drug Discovery Core, Room 6003 Wisconsin Institutes for Medical Research, 1111 Highland Ave, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705. Tel 608-263-8687.
| | - Scott A. Wildman
- UW Carbone Cancer Center Drug Discovery Core, Room 6003 Wisconsin Institutes for Medical Research, 1111 Highland Ave, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705. Tel 608-263-8687.
| | - F. Michael Hoffmann
- McArdle Laboratory for Cancer Research and UW Carbone Cancer Center Drug Discovery Core, Room 7553, Wisconsin Institutes for Medical Research, 1111 Highland Ave, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705. Tel 608-263-8687.
| | - James L. Keck
- Department of Biomolecular Chemistry, Room 1135 Biochemistry Building, 420 Henry Mall, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706. Tel: 608-263-1815. Fax: 608-262-5253.
| |
Collapse
|
43
|
Nguyen HD, Yadav T, Giri S, Saez B, Graubert TA, Zou L. Functions of Replication Protein A as a Sensor of R Loops and a Regulator of RNaseH1. Mol Cell 2017; 65:832-847.e4. [PMID: 28257700 DOI: 10.1016/j.molcel.2017.01.029] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/05/2016] [Accepted: 01/24/2017] [Indexed: 10/20/2022]
Abstract
R loop, a transcription intermediate containing RNA:DNA hybrids and displaced single-stranded DNA (ssDNA), has emerged as a major source of genomic instability. RNaseH1, which cleaves the RNA in RNA:DNA hybrids, plays an important role in R loop suppression. Here we show that replication protein A (RPA), an ssDNA-binding protein, interacts with RNaseH1 and colocalizes with both RNaseH1 and R loops in cells. In vitro, purified RPA directly enhances the association of RNaseH1 with RNA:DNA hybrids and stimulates the activity of RNaseH1 on R loops. An RPA binding-defective RNaseH1 mutant is not efficiently stimulated by RPA in vitro, fails to accumulate at R loops in cells, and loses the ability to suppress R loops and associated genomic instability. Thus, in addition to sensing DNA damage and replication stress, RPA is a sensor of R loops and a regulator of RNaseH1, extending the versatile role of RPA in suppression of genomic instability.
Collapse
Affiliation(s)
- Hai Dang Nguyen
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Tribhuwan Yadav
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Sumanprava Giri
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Borja Saez
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Timothy A Graubert
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA; Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| |
Collapse
|
44
|
Marcu O, Dodson EJ, Alam N, Sperber M, Kozakov D, Lensink MF, Schueler-Furman O. FlexPepDock lessons from CAPRI peptide-protein rounds and suggested new criteria for assessment of model quality and utility. Proteins 2017; 85:445-462. [PMID: 28002624 PMCID: PMC6618814 DOI: 10.1002/prot.25230] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/15/2016] [Accepted: 11/23/2016] [Indexed: 12/21/2022]
Abstract
CAPRI rounds 28 and 29 included, for the first time, peptide-receptor targets of three different systems, reflecting increased appreciation of the importance of peptide-protein interactions. The CAPRI rounds allowed us to objectively assess the performance of Rosetta FlexPepDock, one of the first protocols to explicitly include peptide flexibility in docking, accounting for peptide conformational changes upon binding. We discuss here successes and challenges in modeling these targets: we obtain top-performing, high-resolution models of the peptide motif for cases with known binding sites but there is a need for better modeling of flanking regions, as well as better selection criteria, in particular for unknown binding sites. These rounds have also provided us the opportunity to reassess the success criteria, to better reflect the quality of a peptide-protein complex model. Using all models submitted to CAPRI, we analyze the correlation between current classification criteria and the ability to retrieve critical interface features, such as hydrogen bonds and hotspots. We find that loosening the backbone (and ligand) RMSD threshold, together with a restriction on the side chain RMSD measure, allows us to improve the selection of high-accuracy models. We also suggest a new measure to assess interface hydrogen bond recovery, which is not assessed by the current CAPRI criteria. Finally, we find that surprisingly much can be learned from rather inaccurate models about binding hotspots, suggesting that the current status of peptide-protein docking methods, as reflected by the submitted CAPRI models, can already have a significant impact on our understanding of protein interactions. Proteins 2017; 85:445-462. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Orly Marcu
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, the Hebrew University of Jerusalem, Israel
| | - Emma-Joy Dodson
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, the Hebrew University of Jerusalem, Israel
| | - Nawsad Alam
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, the Hebrew University of Jerusalem, Israel
| | - Michal Sperber
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, the Hebrew University of Jerusalem, Israel
| | - Dima Kozakov
- Department of Applied Mathematics and Statistics, Stony Brooks University, Stony Brook, New York, 11794
| | - Marc F Lensink
- University of Lille, CNRS UMR8576 UGSF, Lille, 59000, France
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, the Hebrew University of Jerusalem, Israel
| |
Collapse
|
45
|
Yan Y, Wen Z, Wang X, Huang SY. Addressing recent docking challenges: A hybrid strategy to integrate template-based and free protein-protein docking. Proteins 2017; 85:497-512. [PMID: 28026062 DOI: 10.1002/prot.25234] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 12/15/2016] [Accepted: 12/16/2016] [Indexed: 12/23/2022]
Abstract
Protein-protein docking is an important computational tool for predicting protein-protein interactions. With the rapid development of proteomics projects, more and more experimental binding information ranging from mutagenesis data to three-dimensional structures of protein complexes are becoming available. Therefore, how to appropriately incorporate the biological information into traditional ab initio docking has been an important issue and challenge in the field of protein-protein docking. To address these challenges, we have developed a Hybrid DOCKing protocol of template-based and template-free approaches, referred to as HDOCK. The basic procedure of HDOCK is to model the structures of individual components based on the template complex by a template-based method if a template is available; otherwise, the component structures will be modeled based on monomer proteins by regular homology modeling. Then, the complex structure of the component models is predicted by traditional protein-protein docking. With the HDOCK protocol, we have participated in the CPARI experiment for rounds 28-35. Out of the 25 CASP-CAPRI targets for oligomer modeling, our HDOCK protocol predicted correct models for 16 targets, ranking one of the top algorithms in this challenge. Our docking method also made correct predictions on other CAPRI challenges such as protein-peptide binding for 6 out of 8 targets and water predictions for 2 out of 2 targets. The advantage of our hybrid docking approach over pure template-based docking was further confirmed by a comparative evaluation on 20 CASP-CAPRI targets. Proteins 2017; 85:497-512. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yumeng Yan
- School of Physics, Huazhong University of Science and Technology, Wuhan Hubei, 430074, People's Republic of China
| | - Zeyu Wen
- School of Physics, Huazhong University of Science and Technology, Wuhan Hubei, 430074, People's Republic of China
| | - Xinxiang Wang
- School of Physics, Huazhong University of Science and Technology, Wuhan Hubei, 430074, People's Republic of China
| | - Sheng-You Huang
- School of Physics, Huazhong University of Science and Technology, Wuhan Hubei, 430074, People's Republic of China
| |
Collapse
|
46
|
wu C, Gan N, Ou C, Tang H, Zhou Y, Cao J. A homogenous “signal-on” aptasensor for antibiotics based on a single stranded DNA binding protein-quantum dot aptamer probe coupling exonuclease-assisted target recycling for signal amplification. RSC Adv 2017. [DOI: 10.1039/c6ra27337h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The method is based on replacement reaction, just by mixing the probes with targets for detection, which is simple and easy for manipulation.
Collapse
Affiliation(s)
- Caiye wu
- Faculty of Marine
- Ningbo University
- Ningbo
- China
- Faculty of Material Science and Chemical Engineering
| | - Ning Gan
- Faculty of Material Science and Chemical Engineering
- Ningbo University
- Ningbo
- China
| | | | - Haiqing Tang
- School of Food Science and Technology
- Zhejiang Pharmaceutical College
- Ningbo
- China
| | - You Zhou
- Faculty of Material Science and Chemical Engineering
- Ningbo University
- Ningbo
- China
| | - Jinxuan Cao
- Faculty of Marine
- Ningbo University
- Ningbo
- China
| |
Collapse
|
47
|
Lensink MF, Velankar S, Wodak SJ. Modeling protein-protein and protein-peptide complexes: CAPRI 6th edition. Proteins 2016; 85:359-377. [PMID: 27865038 DOI: 10.1002/prot.25215] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/19/2022]
Abstract
We present the sixth report evaluating the performance of methods for predicting the atomic resolution structures of protein complexes offered as targets to the community-wide initiative on the Critical Assessment of Predicted Interactions (CAPRI). The evaluation is based on a total of 20,670 predicted models for 8 protein-peptide complexes, a novel category of targets in CAPRI, and 12 protein-protein targets in CAPRI prediction Rounds held during the years 2013-2016. For two of the protein-protein targets, the focus was on the prediction of side-chain conformation and positions of interfacial water molecules. Seven of the protein-protein targets were particularly challenging owing to their multicomponent nature, to conformational changes at the binding site, or to a combination of both. Encouragingly, the very large multiprotein complex with the nucleosome was correctly predicted, and correct models were submitted for the protein-peptide targets, but not for some of the challenging protein-protein targets. Models of acceptable quality or better were obtained for 14 of the 20 targets, including medium quality models for 13 targets and high quality models for 8 targets, indicating tangible progress of present-day computational methods in modeling protein complexes with increased accuracy. Our evaluation suggests that the progress stems from better integration of different modeling tools with docking procedures, as well as the use of more sophisticated evolutionary information to score models. Nonetheless, adequate modeling of conformational flexibility in interacting proteins remains an important area with a crucial need for improvement. Proteins 2017; 85:359-377. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Marc F Lensink
- University of Lille, CNRS UMR8576 UGSF, Lille, 59000, France
| | - Sameer Velankar
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Shoshana J Wodak
- VIB Structural Biology Research Center, VUB Pleinlaan 2, Brussels, 1050, Belgium
| |
Collapse
|
48
|
Xu X, Qiu L, Yan C, Ma Z, Grinter SZ, Zou X. Performance of MDockPP in CAPRI rounds 28-29 and 31-35 including the prediction of water-mediated interactions. Proteins 2016; 85:424-434. [PMID: 27802576 DOI: 10.1002/prot.25203] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/24/2016] [Accepted: 10/24/2016] [Indexed: 01/01/2023]
Abstract
Protein-protein interactions are either through direct contacts between two binding partners or mediated by structural waters. Both direct contacts and water-mediated interactions are crucial to the formation of a protein-protein complex. During the recent CAPRI rounds, a novel parallel searching strategy for predicting water-mediated interactions is introduced into our protein-protein docking method, MDockPP. Briefly, a FFT-based docking algorithm is employed in generating putative binding modes, and an iteratively derived statistical potential-based scoring function, ITScorePP, in conjunction with biological information is used to assess and rank the binding modes. Up to 10 binding modes are selected as the initial protein-protein complex structures for MD simulations in explicit solvent. Water molecules near the interface are clustered based on the snapshots extracted from independent equilibrated trajectories. Then, protein-ligand docking is employed for a parallel search for water molecules near the protein-protein interface. The water molecules generated by ligand docking and the clustered water molecules generated by MD simulations are merged, referred to as the predicted structural water molecules. Here, we report the performance of this protocol for CAPRI rounds 28-29 and 31-35 containing 20 valid docking targets and 11 scoring targets. In the docking experiments, we predicted correct binding modes for nine targets, including one high-accuracy, two medium-accuracy, and six acceptable predictions. Regarding the two targets for the prediction of water-mediated interactions, we achieved models ranked as "excellent" in accordance with the CAPRI evaluation criteria; one of these two targets is considered as a difficult target for structural water prediction. Proteins 2017; 85:424-434. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Xianjin Xu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211, USA
| | - Liming Qiu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211, USA
| | - Chengfei Yan
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211, USA.,Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, 65211, USA
| | - Zhiwei Ma
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211, USA.,Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, 65211, USA
| | - Sam Z Grinter
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211, USA.,Informatics Institute, University of Missouri, Columbia, Missouri, 65211, USA
| | - Xiaoqin Zou
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, 65211, USA.,Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, 65211, USA.,Department of Biochemistry, University of Missouri, Columbia, Missouri, 65211, USA.,Informatics Institute, University of Missouri, Columbia, Missouri, 65211, USA
| |
Collapse
|
49
|
Schindler CEM, Chauvot de Beauchêne I, de Vries SJ, Zacharias M. Protein-protein and peptide-protein docking and refinement using ATTRACT in CAPRI. Proteins 2016; 85:391-398. [PMID: 27785830 DOI: 10.1002/prot.25196] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/13/2016] [Accepted: 09/27/2016] [Indexed: 11/06/2022]
Abstract
The ATTRACT coarse-grained docking approach in combination with various types of atomistic, flexible refinement methods has been applied to predict protein-protein and peptide-protein complexes in CAPRI rounds 28-36. For a large fraction of CAPRI targets (12 out of 18), at least one model of acceptable or better quality was generated, corresponding to a success rate of 67%. In particular, for several peptide-protein complexes excellent predictions were achieved. In several cases, a combination of template-based modeling and extensive molecular dynamics-based refinement yielded medium and even high quality solutions. In one particularly challenging case, the structure of an ubiquitylation enzyme bound to the nucleosome was correctly predicted as a set of acceptable quality solutions. Based on the experience with the CAPRI targets, new interface refinement approaches and methods for ab-initio peptide-protein docking have been developed. Failures and possible improvements of the docking method with respect to scoring and protein flexibility will also be discussed. Proteins 2017; 85:391-398. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Christina E M Schindler
- Physics Department T38, Technische Universität München, Garching, 85748, Germany.,Center for Integrated Protein Science Munich, München, 81377, Germany
| | | | - Sjoerd J de Vries
- Physics Department T38, Technische Universität München, Garching, 85748, Germany
| | - Martin Zacharias
- Physics Department T38, Technische Universität München, Garching, 85748, Germany.,Center for Integrated Protein Science Munich, München, 81377, Germany
| |
Collapse
|
50
|
Transient RNA-DNA Hybrids Are Required for Efficient Double-Strand Break Repair. Cell 2016; 167:1001-1013.e7. [DOI: 10.1016/j.cell.2016.10.001] [Citation(s) in RCA: 259] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/16/2016] [Accepted: 09/29/2016] [Indexed: 11/19/2022]
|