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Chen H, Xu Y, Jin J, Su XD. KaScape: a sequencing-based method for global characterization of protein‒DNA binding affinity. Sci Rep 2023; 13:16595. [PMID: 37789131 PMCID: PMC10547764 DOI: 10.1038/s41598-023-43426-x] [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: 06/20/2023] [Accepted: 09/23/2023] [Indexed: 10/05/2023] Open
Abstract
It is difficult to exhaustively screen all possible DNA binding sequences for a given transcription factor (TF). Here, we developed the KaScape method, in which TFs bind to all possible DNA sequences in the same DNA pool where DNA sequences are prepared by randomized oligo synthesis and the random length can be adjusted to a length such as 4, 5, 6, or 7. After separating bound from unbound double-stranded DNAs (dsDNAs), their sequences are determined by next-generation sequencing. To demonstrate the relative binding affinities of all possible DNA sequences determined by KaScape, we developed three-dimensional KaScape viewing software based on a K-mer graph. We applied KaScape to 12 plant TF family AtWRKY proteins and found that all AtWRKY proteins bound to the core sequence GAC with similar profiles. KaScape can detect not only binding sequences consistent with the consensus W-box "TTGAC(C/T)" but also other sequences with weak affinity. KaScape provides a high-throughput, easy-to-operate, sensitive, and exhaustive method for quantitatively characterizing the relative binding strength of a TF with all possible binding sequences, allowing us to comprehensively characterize the specificity and affinity landscape of transcription factors, particularly for moderate- and low-affinity binding sites.
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Affiliation(s)
- Hong Chen
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Yongping Xu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Jianshi Jin
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing, 100101, People's Republic of China
| | - Xiao-Dong Su
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China.
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2
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Kohl MP, Kompatscher M, Clementi N, Holl L, Erlacher M. Initiation at AUGUG and GUGUG sequences can lead to translation of overlapping reading frames in E. coli. Nucleic Acids Res 2022; 51:271-289. [PMID: 36546769 PMCID: PMC9841429 DOI: 10.1093/nar/gkac1175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/16/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
During initiation, the ribosome is tasked to efficiently recognize open reading frames (ORFs) for accurate and fast translation of mRNAs. A critical step is start codon recognition, which is modulated by initiation factors, mRNA structure, a Shine Dalgarno (SD) sequence and the start codon itself. Within the Escherichia coli genome, we identified more than 50 annotated initiation sites harboring AUGUG or GUGUG sequence motifs that provide two canonical start codons, AUG and GUG, in immediate proximity. As these sites may challenge start codon recognition, we studied if and how the ribosome is accurately guided to the designated ORF, with a special focus on the SD sequence as well as adenine at the fourth coding sequence position (A4). By in vitro and in vivo experiments, we characterized key requirements for unambiguous start codon recognition, but also discovered initiation sites that lead to the translation of both overlapping reading frames. Our findings corroborate the existence of an ambiguous translation initiation mechanism, implicating a multitude of so far unrecognized ORFs and translation products in bacteria.
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Affiliation(s)
- Maximilian P Kohl
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Maria Kompatscher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Nina Clementi
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Lena Holl
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Matthias D Erlacher
- To whom correspondence should be addressed. Tel: +43 512900370256; Fax: +43 512900373100;
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3
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Duan Y, Zhang X, Zhai W, Zhang J, Zhang X, Xu G, Li H, Deng Z, Shi J, Xu Z. Deciphering the Rules of Ribosome Binding Site Differentiation in Context Dependence. ACS Synth Biol 2022; 11:2726-2740. [PMID: 35877551 DOI: 10.1021/acssynbio.2c00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ribosome binding site (RBS) is a crucial element regulating translation. However, the activity of RBS is poorly predictable, because it is strongly affected by the local possible secondary structure, that is, context dependence. By the Flowseq technique, over 20 000 RBS variants were sorted and sequenced, and the translation of multiple genes under the same RBS was quantitatively characterized to evaluate the context dependence of each RBS variant in E. coli. Two regions, (-7 to -2) and (-17 to -12), of RBS were predicted with a higher possibility to pair with each other to slow down the translation initiation. Associations between phenotypes and the intrinsic factors suspected to affect translation efficiency and context dependence of the RBS, including nucleotide bias at each position, free energy, and conservation, were disentangled. The results showed that translation efficiency was influenced more significantly by conservation of the SD region (-16 to -8), while an AC-rich spacer region (-7 to -1) was associated with low context dependence. We confirmed these characteristics using a series of synthesized RBSs. The average correlation between multiple reporters was significantly higher for RBSs with an AC-rich spacer (0.714) compared with a GU-rich spacer (0.286). Overall, we proposed general design criteria to improve programmability and minimize context dependence of RBS. The characteristics unraveled here can be adapted to other bacteria for fine-tuning target-gene expression.
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Affiliation(s)
- Yanting Duan
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Xiaojuan Zhang
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Weiji Zhai
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Jinpeng Zhang
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Xiaomei Zhang
- School of Life Science and Health Engineering, Jiangnan University, Wuxi 214122, China.,Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Guoqiang Xu
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Hui Li
- School of Artificial Intelligence and Computer Science, Jiangnan University, Wuxi 214122, China
| | - Zhaohong Deng
- School of Artificial Intelligence and Computer Science, Jiangnan University, Wuxi 214122, China
| | - Jinsong Shi
- School of Life Science and Health Engineering, Jiangnan University, Wuxi 214122, China.,Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Zhenghong Xu
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
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4
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Translation initiation site of mRNA is selected through dynamic interaction with the ribosome. Proc Natl Acad Sci U S A 2022; 119:e2118099119. [PMID: 35605125 DOI: 10.1073/pnas.2118099119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceRibosomes translate the genetic codes of messenger RNA (mRNA) to make proteins. Translation must begin at the correct initiation site; otherwise, abnormal proteins will be produced. Here, we show that a short ribosome-specific sequence in the upstream followed by an unstructured downstream sequence is a favorable initiation site. Those mRNAs lacking either of these two characteristics do not associate tightly with the ribosome. Initiator transfer RNA (tRNA) and initiation factors facilitate the binding. However, when the downstream site forms structures, initiation factor 3 triggers the dissociation of the accommodated initiator tRNA and the subsequent disassembly of the ribosome-mRNA complex. Thus, initiation factors help the ribosome distinguish unfavorable structured sequences that may not act as the mRNA translation initiation site.
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Zhao L, Wang H, Li P, Sun K, Guan DL, Xu SQ. Genome Size Estimation and Full-Length Transcriptome of Sphingonotus tsinlingensis: Genetic Background of a Drought-Adapted Grasshopper. Front Genet 2021; 12:678625. [PMID: 34322153 PMCID: PMC8313316 DOI: 10.3389/fgene.2021.678625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/14/2021] [Indexed: 11/25/2022] Open
Abstract
Sphingonotus Fieber, 1852 (Orthoptera: Acrididae), is a grasshopper genus comprising approximately 170 species, all of which prefer dry environments such as deserts, steppes, and stony benchlands. In this study, we aimed to examine the adaptation of grasshopper species to arid environments. The genome size of Sphingonotus tsinlingensis was estimated using flow cytometry, and the first high-quality full-length transcriptome of this species was produced. The genome size of S. tsinlingensis is approximately 12.8 Gb. Based on 146.98 Gb of PacBio sequencing data, 221.47 Mb full-length transcripts were assembled. Among these, 88,693 non-redundant isoforms were identified with an N50 value of 2,726 bp, which was markedly longer than previous grasshopper transcriptome assemblies. In total, 48,502 protein-coding sequences were identified, and 37,569 were annotated using public gene function databases. Moreover, 36,488 simple tandem repeats, 12,765 long non-coding RNAs, and 414 transcription factors were identified. According to gene functions, 61 cytochrome P450 (CYP450) and 66 heat shock protein (HSP) genes, which may be associated with drought adaptation of S. tsinlingensis, were identified. We compared the transcriptomes of S. tsinlingensis and two other grasshopper species which were less tolerant to drought, namely Mongolotettix japonicus and Gomphocerus licenti. We observed the expression of CYP450 and HSP genes in S. tsinlingensis were higher. We produced the first full-length transcriptome of a Sphingonotus species that has an ultra-large genome. The assembly characteristics were better than those of all known grasshopper transcriptomes. This full-length transcriptome may thus be used to understand the genetic background and evolution of grasshoppers.
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Affiliation(s)
- Lu Zhao
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Hang Wang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Ping Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Kuo Sun
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - De-Long Guan
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Sheng-Quan Xu
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
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6
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Wen JD, Kuo ST, Chou HHD. The diversity of Shine-Dalgarno sequences sheds light on the evolution of translation initiation. RNA Biol 2020; 18:1489-1500. [PMID: 33349119 DOI: 10.1080/15476286.2020.1861406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Shine-Dalgarno (SD) sequences, the core element of prokaryotic ribosome-binding sites, facilitate mRNA translation by base-pair interaction with the anti-SD (aSD) sequence of 16S rRNA. In contrast to this paradigm, an inspection of thousands of prokaryotic species unravels tremendous SD sequence diversity both within and between genomes, whereas aSD sequences remain largely static. The pattern has led many to suggest unidentified mechanisms for translation initiation. Here we review known translation-initiation pathways in prokaryotes. Moreover, we seek to understand the cause and consequence of SD diversity through surveying recent advances in biochemistry, genomics, and high-throughput genetics. These findings collectively show: (1) SD:aSD base pairing is beneficial but nonessential to translation initiation. (2) The 5' untranslated region of mRNA evolves dynamically and correlates with organismal phylogeny and ecological niches. (3) Ribosomes have evolved distinct usage of translation-initiation pathways in different species. We propose a model portraying the SD diversity shaped by optimization of gene expression, adaptation to environments and growth demands, and the species-specific prerequisite of ribosomes to initiate translation. The model highlights the coevolution of ribosomes and mRNA features, leading to functional customization of the translation apparatus in each organism.
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Affiliation(s)
- Jin-Der Wen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.,Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan
| | - Syue-Ting Kuo
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hsin-Hung David Chou
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan.,Department of Life Science, National Taiwan University, Taipei, Taiwan
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7
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Kuo ST, Jahn RL, Cheng YJ, Chen YL, Lee YJ, Hollfelder F, Wen JD, Chou HHD. Global fitness landscapes of the Shine-Dalgarno sequence. Genome Res 2020; 30:711-723. [PMID: 32424071 PMCID: PMC7263185 DOI: 10.1101/gr.260182.119] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/21/2020] [Indexed: 01/06/2023]
Abstract
Shine-Dalgarno sequences (SD) in prokaryotic mRNA facilitate protein translation by pairing with rRNA in ribosomes. Although conventionally defined as AG-rich motifs, recent genomic surveys reveal great sequence diversity, questioning how SD functions. Here, we determined the molecular fitness (i.e., translation efficiency) of 49 synthetic 9-nt SD genotypes in three distinct mRNA contexts in Escherichia coli. We uncovered generic principles governing the SD fitness landscapes: (1) Guanine contents, rather than canonical SD motifs, best predict the fitness of both synthetic and endogenous SD; (2) the genotype-fitness correlation of SD promotes its evolvability by steadily supplying beneficial mutations across fitness landscapes; and (3) the frequency and magnitude of deleterious mutations increase with background fitness, and adjacent nucleotides in SD show stronger epistasis. Epistasis results from disruption of the continuous base pairing between SD and rRNA. This “chain-breaking” epistasis creates sinkholes in SD fitness landscapes and may profoundly impact the evolution and function of prokaryotic translation initiation and other RNA-mediated processes. Collectively, our work yields functional insights into the SD sequence variation in prokaryotic genomes, identifies a simple design principle to guide bioengineering and bioinformatic analysis of SD, and illuminates the fundamentals of fitness landscapes and molecular evolution.
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Affiliation(s)
- Syue-Ting Kuo
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Ruey-Lin Jahn
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yuan-Ju Cheng
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Lan Chen
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Ju Lee
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Jin-Der Wen
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan.,Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Hsin-Hung David Chou
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan.,Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan
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8
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Saito K, Green R, Buskirk AR. Translational initiation in E. coli occurs at the correct sites genome-wide in the absence of mRNA-rRNA base-pairing. eLife 2020; 9:55002. [PMID: 32065583 PMCID: PMC7043885 DOI: 10.7554/elife.55002] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/14/2020] [Indexed: 12/21/2022] Open
Abstract
Shine-Dalgarno (SD) motifs are thought to play an important role in translational initiation in bacteria. Paradoxically, ribosome profiling studies in E. coli show no correlation between the strength of an mRNA’s SD motif and how efficiently it is translated. Performing profiling on ribosomes with altered anti-Shine-Dalgarno sequences, we reveal a genome-wide correlation between SD strength and ribosome occupancy that was previously masked by other contributing factors. Using the antibiotic retapamulin to trap initiation complexes at start codons, we find that the mutant ribosomes select start sites correctly, arguing that start sites are hard-wired for initiation through the action of other mRNA features. We show that A-rich sequences upstream of start codons promote initiation. Taken together, our genome-wide study reveals that SD motifs are not necessary for ribosomes to determine where initiation occurs, though they do affect how efficiently initiation occurs.
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Affiliation(s)
- Kazuki Saito
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States.,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
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