1
|
Sangeeta, Mishra SK, Bhattacherjee A. Role of Shape Deformation of DNA-Binding Sites in Regulating the Efficiency and Specificity in Their Recognition by DNA-Binding Proteins. JACS AU 2024; 4:2640-2655. [PMID: 39055163 PMCID: PMC11267559 DOI: 10.1021/jacsau.4c00393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 07/27/2024]
Abstract
Accurate transcription of genetic information is crucial, involving precise recognition of the binding motifs by DNA-binding proteins. While some proteins rely on short-range hydrophobic and hydrogen bonding interactions at binding sites, others employ a DNA shape readout mechanism for specific recognition. In this mechanism, variations in DNA shape at the binding motif resulted from either inherent flexibility or binding of proteins at adjacent sites are sensed and capitalized by the searching proteins to locate them specifically. Through extensive computer simulations, we investigate both scenarios to uncover the underlying mechanism and origin of specificity in the DNA shape readout mechanism. Our findings reveal that deformation in shape at the binding motif creates an entropy funnel, allowing information about altered shapes to manifest as fluctuations in minor groove widths. This signal enhances the efficiency of nonspecific search of nearby proteins by directing their movement toward the binding site, primarily driven by a gain in entropy. We propose this as a generic mechanism for DNA shape readout, where specificity arises from the alignment between the molecular frustration of the searching protein and the ruggedness of the entropic funnel governed by molecular features of the protein and arrangement of the DNA bases at the binding site, respectively.
Collapse
Affiliation(s)
- Sangeeta
- School of Computational & Integrative
Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sujeet Kumar Mishra
- School of Computational & Integrative
Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Arnab Bhattacherjee
- School of Computational & Integrative
Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| |
Collapse
|
2
|
Murthy S, Dey U, Olymon K, Abbas E, Yella VR, Kumar A. Discerning the Role of DNA Sequence, Shape, and Flexibility in Recognition by Drosophila Transcription Factors. ACS Chem Biol 2024; 19:1533-1543. [PMID: 38902964 DOI: 10.1021/acschembio.4c00202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The precise spatial and temporal orchestration of gene expression is crucial for the ontogeny of an organism and is mainly governed by transcription factors (TFs). The mechanism of recognition of cognate sites amid millions of base pairs in the genome by TFs is still incompletely understood. In this study, we focus on DNA sequence composition, shape, and flexibility preferences of 28 quintessential TFs from Drosophila melanogaster that are critical to development and body patterning mechanisms. Our study finds that TFs exhibit distinct predilections for DNA shape, flexibility, and sequence compositions in the proximity of transcription factor binding sites (TFBSs). Notably, certain zinc finger proteins prefer GC-rich areas with less negative propeller twist, while homeodomains mainly seek AT-rich regions with a more negative propeller twist at their sites. Intriguingly, while numerous cofactors share similar binding site preferences and bind closer to each other in the genome, some cofactors that have different preferences bind farther apart. These findings shed light on TF DNA recognition and provide novel insights into possible cofactor binding and transcriptional regulation mechanisms.
Collapse
Affiliation(s)
- Smrithi Murthy
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam 784028, India
| | - Upalabdha Dey
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam 784028, India
| | - Kaushika Olymon
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam 784028, India
| | - Eshan Abbas
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam 784028, India
| | - Venkata Rajesh Yella
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Guntur 520002, India
| | - Aditya Kumar
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam 784028, India
| |
Collapse
|
3
|
Chen N, Yu J, Liu Z, Meng L, Li X, Wong KC. Discovering DNA shape motifs with multiple DNA shape features: generalization, methods, and validation. Nucleic Acids Res 2024; 52:4137-4150. [PMID: 38572749 PMCID: PMC11077088 DOI: 10.1093/nar/gkae210] [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: 07/06/2023] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 04/05/2024] Open
Abstract
DNA motifs are crucial patterns in gene regulation. DNA-binding proteins (DBPs), including transcription factors, can bind to specific DNA motifs to regulate gene expression and other cellular activities. Past studies suggest that DNA shape features could be subtly involved in DNA-DBP interactions. Therefore, the shape motif annotations based on intrinsic DNA topology can deepen the understanding of DNA-DBP binding. Nevertheless, high-throughput tools for DNA shape motif discovery that incorporate multiple features altogether remain insufficient. To address it, we propose a series of methods to discover non-redundant DNA shape motifs with the generalization to multiple motifs in multiple shape features. Specifically, an existing Gibbs sampling method is generalized to multiple DNA motif discovery with multiple shape features. Meanwhile, an expectation-maximization (EM) method and a hybrid method coupling EM with Gibbs sampling are proposed and developed with promising performance, convergence capability, and efficiency. The discovered DNA shape motif instances reveal insights into low-signal ChIP-seq peak summits, complementing the existing sequence motif discovery works. Additionally, our modelling captures the potential interplays across multiple DNA shape features. We provide a valuable platform of tools for DNA shape motif discovery. An R package is built for open accessibility and long-lasting impact: https://zenodo.org/doi/10.5281/zenodo.10558980.
Collapse
Affiliation(s)
- Nanjun Chen
- Department of Computer Science, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
| | - Jixiang Yu
- Department of Computer Science, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
| | - Zhe Liu
- Department of Computer Science, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
| | - Lingkuan Meng
- Department of Computer Science, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
| | - Xiangtao Li
- School of Artificial Intelligence, Jilin University, Changchun City, Jilin Province, China
| | - Ka-Chun Wong
- Department of Computer Science, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
- Hong Kong Institute of Data Science, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
| |
Collapse
|
4
|
Vernon TN, Terrell JR, Albrecht AV, Germann MW, Wilson WD, Poon GMK. Dissection of integrated readout reveals the structural thermodynamics of DNA selection by transcription factors. Structure 2024; 32:83-96.e4. [PMID: 38042148 DOI: 10.1016/j.str.2023.11.003] [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: 08/08/2023] [Revised: 10/12/2023] [Accepted: 11/07/2023] [Indexed: 12/04/2023]
Abstract
Nucleobases such as inosine have been extensively utilized to map direct contacts by proteins in the DNA groove. Their deployment as targeted probes of dynamics and hydration, which are dominant thermodynamic drivers of affinity and specificity, has been limited by a paucity of suitable experimental models. We report a joint crystallographic, thermodynamic, and computational study of the bidentate complex of the arginine side chain with a Watson-Crick guanine (Arg×GC), a highly specific configuration adopted by major transcription factors throughout the eukaryotic branches in the Tree of Life. Using the ETS-family factor PU.1 as a high-resolution structural framework, inosine substitution for guanine resulted in a sharp dissection of conformational dynamics and hydration and elucidated their role in the DNA specificity of PU.1. Our work suggests an under-exploited utility of modified nucleobases in untangling the structural thermodynamics of interactions, such as the Arg×GC motif, where direct and indirect readout are tightly integrated.
Collapse
Affiliation(s)
- Tyler N Vernon
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA
| | - J Ross Terrell
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA
| | - Amanda V Albrecht
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA
| | - Markus W Germann
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA; Department of Biology, Georgia State University, Atlanta, GA 30302, USA.
| | - W David Wilson
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA; Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302, USA.
| | - Gregory M K Poon
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA; Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302, USA.
| |
Collapse
|
5
|
Memon AA, Fu X, Fan XY, Xu L, Xiao J, Rahman MU, Yang X, Yao YF, Deng Z, Ma W. Substrate DNA Promoting Binding of Mycobacterium tuberculosis MtrA by Facilitating Dimerization and Interpretation of Affinity by Minor Groove Width. Microorganisms 2023; 11:2505. [PMID: 37894163 PMCID: PMC10609481 DOI: 10.3390/microorganisms11102505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
In order to deepen the understanding of the role and regulation mechanisms of prokaryotic global transcription regulators in complex processes, including virulence, the associations between the affinity and binding sequences of Mycobacterium tuberculosis MtrA have been explored extensively. Analysis of MtrA 294 diversified 26 bp binding sequences revealed that the sequence similarity of fragments was not simply associated with affinity. The unique variation patterns of GC content and periodical and sequential fluctuation of affinity contribution curves were observed along the sequence in this study. Furthermore, docking analysis demonstrated that the structure of the dimer MtrA-DNA (high affinity) was generally consistent with other OmpR family members, while Arg 219 and Gly 220 of the wing domain interacted with the minor groove. The results of the binding box replacement experiment proved that box 2 was essential for binding, which implied the differential roles of the two boxes in the binding process. Furthermore, the results of the substitution of the nucleotide at the 20th and/or 21st positions indicated that the affinity was negatively associated with the value of minor groove width precisely at the 21st position. The dimerization of the unphosphorylated MtrA facilitated by a low-affinity DNA fragment was observed for the first time. However, the proportion of the dimer was associated with the affinity of substrate DNA, which further suggested that the affinity was actually one characteristic of the stability of dimers. Based on the finding of 17 inter-molecule hydrogen bonds identified in the interface of the MtrA dimer, including 8 symmetric complementary ones in the conserved α4-β5-α5 face, we propose that hydrogen bonds should be considered just as important as salt bridges and the hydrophobic patch in the dimerization. Our comprehensive study on a large number of binding fragments with quantitative affinity values provided new insight into the molecular mechanism of dimerization, binding specificity and affinity determination of MtrA and clues for solving the puzzle of how global transcription factors regulate a large quantity of target genes.
Collapse
Affiliation(s)
- Aadil Ahmed Memon
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiang Fu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiao-Yong Fan
- Shanghai Institute of Infectious Diseases and Biosecurity, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Lingyun Xu
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Jihua Xiao
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Mueed Ur Rahman
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiaoqi Yang
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Institutes of Medical Sciences, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Ma
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| |
Collapse
|
6
|
Stellwagen E, Stellwagen NC. Monovalent cation localization in DNA A-tracts with different sequences. Electrophoresis 2023; 44:1414-1422. [PMID: 37354056 DOI: 10.1002/elps.202300063] [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: 03/29/2023] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 06/26/2023]
Abstract
The free solution mobilities of 26-base pair (bp) DNA oligomers containing A-tracts with and without internal ApT steps have been measured by capillary electrophoresis, using the mobility of a 26-bp random-sequence oligomer as a reference. The background electrolytes (BGEs) contained mixtures of Li+ and tetrapropylammonium (TPA+ ) ions, keeping the total cation concentration constant at 0.3 M. The mobility ratios equaled 1.00 in 0.3 M TPA+ , indicating that the A-tract and reference oligomers had the same B-form conformation in this BGE. With increasing [Li+ ], the mobility ratio decreased as Li+ ions became localized in the A-tract minor groove, suggesting that the A-tract was now in the B* conformation. If the A-tract contained an internal ApT step and the oligomer contained less than ∼50% A + T, the mobility ratio reached a reduced plateau value that remained constant as the [Li+ ] increased to 0.3 M. However, for A-tracts without an internal ApT step and for A-tracts embedded in oligomers containing more than 50% A + T, the mobility ratios increased again at high [Li+ ], eventually reaching a plateau value of 1.00. Hence, DNA A-tracts in solution appear to exist as mixtures of the B and B* conformations, with the fractional concentration of each conformer depending on the [Li+ ], the A-tract sequence, and the total A + T content of the oligomer.
Collapse
Affiliation(s)
- Earle Stellwagen
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, USA
| | | |
Collapse
|
7
|
Samee MAH. Noncanonical binding of transcription factors: time to revisit specificity? Mol Biol Cell 2023; 34:pe4. [PMID: 37486893 PMCID: PMC10398899 DOI: 10.1091/mbc.e22-08-0325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 06/05/2023] [Accepted: 06/21/2023] [Indexed: 07/26/2023] Open
Abstract
Transcription factors (TFs) are one of the most studied classes of DNA-binding proteins that have a direct functional impact on gene transcription and thus, on human physiology and disease. The mechanisms that TFs use for recognizing target DNA binding sites have been studied for nearly five decades, yet they remain poorly understood. It is classically assumed that a TF recognizes a specific sequence pattern, or motif, as its binding sites. However, recent studies are consistently finding examples of noncanonical binding, that is, TFs binding at sites that do not resemble their sequence motifs. Here we review the current literature on four major types of noncanonical TF binding, namely binding based on DNA shape readout, at Guanine-quadruplex structures, at repeat sequences, and bispecific binding. These examples point to a critical need for studies to unify our current observations, many of which are at odds with the "one TF, one motif" view, into a more comprehensive definition of the DNA-binding specificity of TFs.
Collapse
|
8
|
Sawyer JM, Passow KT, Harki DA. Synthesis and photophysical characterization of fluorescent indole nucleoside analogues. RSC Adv 2023; 13:16369-16376. [PMID: 37266506 PMCID: PMC10230516 DOI: 10.1039/d3ra03457g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/03/2023] Open
Abstract
Fluorescent nucleosides are useful chemical tools for biochemical research and are frequently incorporated into nucleic acids for a variety of applications. The most widely utilized fluorescent nucleoside is 2-aminopurine-2'-deoxyribonucleoside (2APN). However, 2APN is limited by a moderate Stokes shift, molar extinction coefficient, and quantum yield. We recently reported 4-cyanoindole-2'-deoxyribonucleoside (4CIN), which offers superior photophysical characteristics in comparison to 2APN. To further improve upon 4CIN, a focused library of additional analogues combining the structural features of 2APN and 4CIN were synthesized and their photophysical properties were quantified. Nucleosides 2-6 were found to possess diverse photophysical properties with some features superior to 4CIN. In addition, the structure-function relationship data gained from 1-6 can inform the design of next-generation fluorescent indole nucleosides.
Collapse
Affiliation(s)
- Jacob M Sawyer
- Department of Chemistry, University of Minnesota Minneapolis Minnesota 55455 USA
| | - Kellan T Passow
- Department of Medicinal Chemistry, University of Minnesota Minneapolis Minnesota 55455 USA
| | - Daniel A Harki
- Department of Chemistry, University of Minnesota Minneapolis Minnesota 55455 USA
- Department of Medicinal Chemistry, University of Minnesota Minneapolis Minnesota 55455 USA
| |
Collapse
|
9
|
Luo S, Xiong D, Zhao X, Duan L. An Attempt of Seeking Favorable Binding Free Energy Prediction Schemes Considering the Entropic Effect on Fis-DNA Binding. J Phys Chem B 2023; 127:1312-1324. [PMID: 36735878 DOI: 10.1021/acs.jpcb.2c07811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Protein-DNA binding mechanisms in a complex manner are essential for understanding many biological processes. Over the past decades, numerous experiments and calculations have analyzed the specificity of protein-DNA binding. However, the accuracy of binding free energy prediction for multi-base DNA systems still needs to be improved. Fis is a DNA-binding protein that regulates various transcription and recombination reactions. In the present work, we tested several methods of predict binding free energy based on this system to find a favorable prediction scheme and explore the binding mechanism of Fis protein and DNA. Two solvent models (explicit and implicit solvent models) were chosen for the dynamics process, and the predicted binding free energy was more accurate under the explicit solvent model. When different Poisson-Boltzmann/Generalized Born (PB/GB) models were tested for DNA force fields (BSC1 and OL15), it was found that the binding free energy predicted by the selected OL15 force field performed better and the correlation between predicted and experimental values was improved with the increasing interior dielectric constant (Dk). Finally, using Dk = 8, the GBOBC1 model combined with interaction entropy (IE), which was calculated for entropic contribution (GBOBC1_IE_8), was screened out for the binding free energy prediction and analysis of the Fis-DNA system, and the validity of the method was further verified by testing the Cren7-DNA system. By performing conformational analysis of the minor groove, it was found that mutation of the DNA central sequence A/T to C/G and deletion of the guanine 2-amino group would change the minor groove width and thus affect the formation of the major groove, altering the interaction and atomic contact between the protein and the major groove, thus changing the binding affinity of Fis and DNA. Hopefully, the series of tests in this work can shed some light on the related studies of protein and DNA systems.
Collapse
Affiliation(s)
- Song Luo
- School of Physics and Electronics, Shandong Normal University, Jinan, Shandong250014, China
| | - Danyang Xiong
- School of Physics and Electronics, Shandong Normal University, Jinan, Shandong250014, China
| | - Xiaoyu Zhao
- School of Physics and Electronics, Shandong Normal University, Jinan, Shandong250014, China
| | - Lili Duan
- School of Physics and Electronics, Shandong Normal University, Jinan, Shandong250014, China
| |
Collapse
|
10
|
Abstract
![]()
We
explore the process of base-flipping for four central bases,
adenine, guanine, cytosine, and thymine, in a deoxyribonucleic acid
(DNA) duplex using the energy landscape perspective. NMR imino-proton
exchange and fluorescence correlation spectroscopy studies have been
used in previous experiments to obtain lifetimes for bases in paired
and extrahelical states. However, the difference of almost 4 orders
of magnitude in the base-flipping rates obtained by the two methods
implies that they are exploring different pathways and possibly different
open states. Our results support the previous suggestion that minor
groove opening may be favored by distortions in the DNA backbone and
reveal links between sequence effects and the direction of opening,
i.e., whether the base flips toward the major or the minor groove
side. In particular, base flipping along the minor groove pathway
was found to align toward the 5′ side of the backbone. We find
that bases align toward the 3′ side of the backbone when flipping
along the major groove pathway. However, in some cases for cytosine
and thymine, the base flipping along the major groove pathway also
aligns toward the 5′ side. The sequence effect may be caused
by the polar interactions between the flipping-base and its neighboring
bases on either of the strands. For guanine flipping toward the minor
groove side, we find that the equilibrium constant for opening is
large compared to flipping via the major groove. We find that the
estimated rates of base opening, and hence the lifetimes of the closed
state, obtained for thymine flipping through small and large angles
along the major groove differ by 6 orders of magnitude, whereas for
thymine flipping through small angles along the minor groove and large
angles along the major groove, the rates differ by 3 orders of magnitude.
Collapse
Affiliation(s)
- Nicy
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K
| | - Debayan Chakraborty
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - David J. Wales
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U.K
| |
Collapse
|
11
|
Facilitated Dissociation of Nucleoid Associated Proteins from DNA in the Bacterial Confinement. Biophys J 2022; 121:1119-1133. [PMID: 35257784 PMCID: PMC9034294 DOI: 10.1016/j.bpj.2022.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/04/2021] [Accepted: 03/01/2022] [Indexed: 11/20/2022] Open
Abstract
Transcription machinery depends on the temporal formation of protein-DNA complexes. Recent experiments demonstrated that not only the formation but also the lifetime of such complexes can affect the transcriptional machinery. In parallel, in vitro single-molecule studies showed that nucleoid-associated proteins (NAPs) leave the DNA rapidly as the bulk concentration of the protein increases via facilitated dissociation (FD). Nevertheless, whether such a concentration-dependent mechanism is functional in a bacterial cell, in which NAP levels and the 3d chromosomal structure are often coupled, is not clear a priori. Here, by using extensive coarse-grained molecular simulations, we model the unbinding of specific and nonspecific dimeric NAPs from a high-molecular-weight circular DNA molecule in a cylindrical structure mimicking the cellular confinement of a bacterial chromosome. Our simulations confirm that physiologically relevant peak protein levels (tens of micromolar) lead to highly compact chromosomal structures. This compaction results in rapid off rates (shorter DNA residence times) for specifically DNA-binding NAPs, such as the factor for inversion stimulation, which mostly dissociate via a segmental jump mechanism. Contrarily, for nonspecific NAPs, which are more prone to leave their binding sites via 1d sliding, the off rates decrease as the protein levels increase. The simulations with restrained chromosome models reveal that chromosome compaction is in favor of faster dissociation but only for specific proteins, and nonspecific proteins are not affected by the chromosome compaction. Overall, our results suggest that the cellular concentration level of a structural DNA-binding protein can be highly intermingled with its DNA residence time.
Collapse
|
12
|
Kamagata K, Itoh Y, Tan C, Mano E, Wu Y, Mandali S, Takada S, Johnson RC. Testing mechanisms of DNA sliding by architectural DNA-binding proteins: dynamics of single wild-type and mutant protein molecules in vitro and in vivo. Nucleic Acids Res 2021; 49:8642-8664. [PMID: 34352099 PMCID: PMC8421229 DOI: 10.1093/nar/gkab658] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/10/2021] [Accepted: 07/22/2021] [Indexed: 01/06/2023] Open
Abstract
Architectural DNA-binding proteins (ADBPs) are abundant constituents of eukaryotic or bacterial chromosomes that bind DNA promiscuously and function in diverse DNA reactions. They generate large conformational changes in DNA upon binding yet can slide along DNA when searching for functional binding sites. Here we investigate the mechanism by which ADBPs diffuse on DNA by single-molecule analyses of mutant proteins rationally chosen to distinguish between rotation-coupled diffusion and DNA surface sliding after transient unbinding from the groove(s). The properties of yeast Nhp6A mutant proteins, combined with molecular dynamics simulations, suggest Nhp6A switches between two binding modes: a static state, in which the HMGB domain is bound within the minor groove with the DNA highly bent, and a mobile state, where the protein is traveling along the DNA surface by means of its flexible N-terminal basic arm. The behaviors of Fis mutants, a bacterial nucleoid-associated helix-turn-helix dimer, are best explained by mobile proteins unbinding from the major groove and diffusing along the DNA surface. Nhp6A, Fis, and bacterial HU are all near exclusively associated with the chromosome, as packaged within the bacterial nucleoid, and can be modeled by three diffusion modes where HU exhibits the fastest and Fis the slowest diffusion.
Collapse
Affiliation(s)
- Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Yuji Itoh
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Cheng Tan
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Eriko Mano
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Yining Wu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Sridhar Mandali
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Reid C Johnson
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737, USA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
13
|
Dziuba D, Didier P, Ciaco S, Barth A, Seidel CAM, Mély Y. Fundamental photophysics of isomorphic and expanded fluorescent nucleoside analogues. Chem Soc Rev 2021; 50:7062-7107. [PMID: 33956014 DOI: 10.1039/d1cs00194a] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Fluorescent nucleoside analogues (FNAs) are structurally diverse mimics of the natural essentially non-fluorescent nucleosides which have found numerous applications in probing the structure and dynamics of nucleic acids as well as their interactions with various biomolecules. In order to minimize disturbance in the labelled nucleic acid sequences, the FNA chromophoric groups should resemble the natural nucleobases in size and hydrogen-bonding patterns. Isomorphic and expanded FNAs are the two groups that best meet the criteria of non-perturbing fluorescent labels for DNA and RNA. Significant progress has been made over the past decades in understanding the fundamental photophysics that governs the spectroscopic and environmentally sensitive properties of these FNAs. Herein, we review recent advances in the spectroscopic and computational studies of selected isomorphic and expanded FNAs. We also show how this information can be used as a rational basis to design new FNAs, select appropriate sequences for optimal spectroscopic response and interpret fluorescence data in FNA applications.
Collapse
Affiliation(s)
- Dmytro Dziuba
- Laboratoire de Bioimagerie et Pathologies, UMR 7021, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch, France.
| | - Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch, France.
| | - Stefano Ciaco
- Laboratoire de Bioimagerie et Pathologies, UMR 7021, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch, France. and Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, 53100 Siena, Italy
| | - Anders Barth
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Claus A M Seidel
- Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Yves Mély
- Laboratoire de Bioimagerie et Pathologies, UMR 7021, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch, France.
| |
Collapse
|
14
|
Mantela M, Morphis A, Lambropoulos K, Simserides C, Di Felice R. Effects of Structural Dynamics on Charge Carrier Transfer in B-DNA: A Combined MD and RT-TDDFT Study. J Phys Chem B 2021; 125:3986-4003. [PMID: 33857373 DOI: 10.1021/acs.jpcb.0c11489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hole transfer along the axis of duplex DNA has been the focus of physical chemistry research for decades, with implications in diverse fields, from nanotechnology to cell oxidative damage. Computational approaches are particularly amenable for this problem, to complement experimental data for interpretation of transfer mechanisms. To be predictive, computational results need to account for the inherent mobility of biological molecules during the time frame of experimental measurements. Here, we address the structural variability of B-DNA and its effects on hole transfer in a combined molecular dynamics (MD) and real-time time-dependent density functional theory (RT-TDDFT) study. Our results show that quantities that characterize the charge transfer process, such as the time-dependent dipole moment and hole population at a specific site, are sensitive to structural changes that occur on the nanosecond time scale. We extend the range of physical properties for which such a correlation has been observed, further establishing the fact that quantitative computational data on charge transfer properties should include statistical averages. Furthermore, we use the RT-TDDFT results to assess an efficient tight-binding method suitable for high-throughput predictions. We demonstrate that charge transfer, although affected by structural variability, on average, remains strong in AA and GG dimers.
Collapse
Affiliation(s)
- Marilena Mantela
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | - Andreas Morphis
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | - Konstantinos Lambropoulos
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | - Constantinos Simserides
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | | |
Collapse
|
15
|
Faltejsková K, Jakubec D, Vondrášek J. Hydrophobic Amino Acids as Universal Elements of Protein-Induced DNA Structure Deformation. Int J Mol Sci 2020; 21:ijms21113986. [PMID: 32498246 PMCID: PMC7312683 DOI: 10.3390/ijms21113986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/01/2022] Open
Abstract
Interaction with the DNA minor groove is a significant contributor to specific sequence recognition in selected families of DNA-binding proteins. Based on a statistical analysis of 3D structures of protein–DNA complexes, we propose that distortion of the DNA minor groove resulting from interactions with hydrophobic amino acid residues is a universal element of protein–DNA recognition. We provide evidence to support this by associating each DNA minor groove-binding amino acid residue with the local dimensions of the DNA double helix using a novel algorithm. The widened DNA minor grooves are associated with high GC content. However, some AT-rich sequences contacted by hydrophobic amino acids (e.g., phenylalanine) display extreme values of minor groove width as well. For a number of hydrophobic amino acids, distinct secondary structure preferences could be identified for residues interacting with the widened DNA minor groove. These results hold even after discarding the most populous families of minor groove-binding proteins.
Collapse
Affiliation(s)
- Kateřina Faltejsková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10 Prague 6, Czech Republic;
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czech Republic
| | - David Jakubec
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10 Prague 6, Czech Republic;
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 40 Prague 2, Czech Republic
- Correspondence: (D.J.); (J.V.); Tel.: +420-220183267 (J.V.)
| | - Jiří Vondrášek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10 Prague 6, Czech Republic;
- Correspondence: (D.J.); (J.V.); Tel.: +420-220183267 (J.V.)
| |
Collapse
|
16
|
Fis Contributes to Resistance of Pseudomonas aeruginosa to Ciprofloxacin by Regulating Pyocin Synthesis. J Bacteriol 2020; 202:JB.00064-20. [PMID: 32205461 DOI: 10.1128/jb.00064-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/16/2020] [Indexed: 12/31/2022] Open
Abstract
Factor for inversion stimulation (Fis) is a versatile DNA binding protein that plays an important role in coordinating bacterial global gene expression in response to growth phases and environmental stresses. Previously, we demonstrated that Fis regulates the type III secretion system (T3SS) in Pseudomonas aeruginosa In this study, we explored the role of Fis in the antibiotic resistance of P. aeruginosa and found that mutation of the fis gene increases the bacterial susceptibility to ciprofloxacin. We further demonstrated that genes related to pyocin biosynthesis are upregulated in the fis mutant. The pyocins are produced in response to genotoxic agents, including ciprofloxacin, and the release of pyocins results in lysis of the producer cell. Thus, pyocin biosynthesis genes sensitize P. aeruginosa to ciprofloxacin. We found that PrtN, the positive regulator of the pyocin biosynthesis genes, is upregulated in the fis mutant. Genetic experiments and electrophoretic mobility shift assays revealed that Fis directly binds to the promoter region of prtN and represses its expression. Therefore, our results revealed novel Fis-mediated regulation on pyocin production and bacterial resistance to ciprofloxacin in P. aeruginosa IMPORTANCE Pseudomonas aeruginosa is an important opportunistic pathogenic bacterium that causes various acute and chronic infections in human, especially in patients with compromised immunity, cystic fibrosis (CF), and/or severe burn wounds. About 60% of cystic fibrosis patients have a chronic respiratory infection caused by P. aeruginosa The bacterium is intrinsically highly resistant to antibiotics, which greatly increases difficulties in clinical treatment. Therefore, it is critical to understand the mechanisms and the regulatory pathways that are involved in antibiotic resistance. In this study, we elucidated a novel regulatory pathway that controls the bacterial resistance to fluoroquinolone antibiotics, which enhances our understanding of how P. aeruginosa responds to ciprofloxacin.
Collapse
|
17
|
Zhou J, Gao Z, Zhang H, Dong Y. Crystal structure of the nucleoid-associated protein Fis (PA4853) from Pseudomonas aeruginosa. Acta Crystallogr F Struct Biol Commun 2020; 76:209-215. [PMID: 32356522 PMCID: PMC7193516 DOI: 10.1107/s2053230x20005427] [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: 02/26/2020] [Accepted: 04/18/2020] [Indexed: 11/10/2022] Open
Abstract
Factor for inversion stimulation (Fis) is a versatile bacterial nucleoid-associated protein that can directly bind and bend DNA to influence DNA topology. It also plays crucial roles in regulating bacterial virulence factors and in optimizing bacterial adaptation to various environments. Fis from Pseudomonas aeruginosa (PA4853, referred to as PaFis) has recently been found to be required for virulence by regulating the expression of type III secretion system (T3SS) genes. PaFis can specifically bind to the promoter region of exsA, which functions as a T3SS master regulator, to regulate its expression and plays an essential role in transcription elongation from exsB to exsA. Here, the crystal structure of PaFis, which is composed of a four-helix bundle and forms a homodimer, is reported. PaFis shows remarkable structural similarities to the well studied Escherichia coli Fis (EcFis), including an N-terminal flexible loop and a C-terminal helix-turn-helix (HTH) motif. However, the critical residues for Hin-catalyzed DNA inversion in the N-terminal loop of EcFis are not conserved in PaFis and further studies are required to investigate its exact role. A gel-electrophoresis mobility-shift assay showed that PaFis can efficiently bind to the promoter region of exsA. Structure-based mutagenesis revealed that several conserved basic residues in the HTH motif play essential roles in DNA binding. These structural and biochemical studies may help in understanding the role of PaFis in the regulation of T3SS expression and in virulence.
Collapse
Affiliation(s)
- Juan Zhou
- Institute of Health Sciences and School of Life Science, Anhui University, Hefei, Anhui 230601, People’s Republic of China
| | - Zengqiang Gao
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Heng Zhang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Yuhui Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| |
Collapse
|
18
|
Giri M, Maulik A, Singh M. Signatures of Specific DNA Binding by the AT-Rich Interaction Domain of BAF250a. Biochemistry 2019; 59:100-113. [PMID: 31825600 DOI: 10.1021/acs.biochem.9b00852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The AT-rich interaction domain (ARID) containing BAF250a is a subunit of the BAF-A class of SWI/SNF chromatin remodeling complexes. The ARID belongs to a family of conserved DNA binding domains found in several eukaryotic proteins; however, its exact contribution to BAF250a function and the mechanism of its DNA binding are not well understood. Here we have probed the interaction of the BAF250a ARID with three different double-stranded DNA (dsDNA) sequences to understand its DNA binding properties. A comprehensive biophysical and thermodynamic study using nuclear magnetic resonance (NMR) spectroscopy and isothermal titration calorimetry revealed the complex nature of BAF250a ARID-DNA interactions. The thermodynamic signatures of the BAF250a ARID with 12 A-T bp dsDNA (AT-12) are distinct from those of 12 G-C bp dsDNA (GC-12) or 12 bp Dickerson dodecamer DNA (DD-12) sequences. We observed that the binding of the BAF250a ARID with AT-12 DNA is enthalpically driven in a tested temperature range of 5-25 °C. BAF250a ARID/AT-12 DNA interaction exhibited a larger negative calorimetric specific heat change (ΔCp) compared to that of BAF250a ARID/GC-12 DNA or BAF250a ARID/DD-12 DNA interactions. In the presence of salt (NaCl), ARID/AT-12 DNA binding was less perturbed than ARID/GC-12 DNA or ARID/DD-12 DNA binding. Overall, these results show that BAF250a ARID/AT-12 DNA interaction has signatures of "specific" binding. Furthermore, using NMR chemical shift perturbation experiments, we have identified DNA binding residues on the BAF250a ARID and generated a data-driven HADDOCK model of the ARID/DNA complex that was further supported by mutating key lysine residues that were found to be important for DNA binding.
Collapse
Affiliation(s)
- Malyasree Giri
- Molecular Biophysics Unit , Indian Institute of Science , Bengaluru 560012 , India
| | - Aditi Maulik
- Molecular Biophysics Unit , Indian Institute of Science , Bengaluru 560012 , India
| | - Mahavir Singh
- Molecular Biophysics Unit , Indian Institute of Science , Bengaluru 560012 , India.,NMR Research Centre , Indian Institute of Science , Bengaluru 560012 , India
| |
Collapse
|
19
|
Pataskar A, Vanderlinden W, Emmerig J, Singh A, Lipfert J, Tiwari VK. Deciphering the Gene Regulatory Landscape Encoded in DNA Biophysical Features. iScience 2019; 21:638-649. [PMID: 31731201 PMCID: PMC6889597 DOI: 10.1016/j.isci.2019.10.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 10/20/2019] [Accepted: 10/24/2019] [Indexed: 01/24/2023] Open
Abstract
Gene regulation in higher organisms involves a sophisticated interplay between genetic and epigenetic mechanisms. Despite advances, the logic in selective usage of certain genomic regions as regulatory elements remains unclear. Here we show that the inherent biophysical properties of the DNA encode epigenetic state and the underlying regulatory potential. We find that the propeller twist (ProT) level is indicative of genomic location of the regulatory elements, their strength, the affinity landscape of transcription factors, and distribution in the nuclear 3D space. We experimentally show that ProT levels confer increased DNA flexibility and surface accessibility, and thus potentially primes usage of high ProT regions as regulatory elements. ProT levels also correlate with occurrence and phenotypic consequences of mutations. Interestingly, cell-fate switches involve a transient usage of low ProT regulatory elements. Altogether, our work provides unprecedented insights into the gene regulatory landscape encoded in the DNA biophysical features. DNA shape features encode genomic surface accessibility and flexibility High ProT is a deterministic feature of enhancers ProT levels correlate with nuclear organization of epigenetic states Cell-fate switches involve a transient usage of low ProT regulatory elements
Collapse
Affiliation(s)
- Abhijeet Pataskar
- Netherlands Cancer Institute, Amsterdam, the Netherlands; Former Address: Institute of Molecular Biology, 55128 Mainz, Germany
| | - Willem Vanderlinden
- Department of Physics and Center for NanoScience, LMU Munich, 80799 Munich, Germany
| | - Johannes Emmerig
- Department of Physics and Center for NanoScience, LMU Munich, 80799 Munich, Germany
| | - Aditi Singh
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queens University Belfast, Belfast BT9 7BL, UK
| | - Jan Lipfert
- Department of Physics and Center for NanoScience, LMU Munich, 80799 Munich, Germany
| | - Vijay K Tiwari
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queens University Belfast, Belfast BT9 7BL, UK; Former Address: Institute of Molecular Biology, 55128 Mainz, Germany.
| |
Collapse
|
20
|
Loth K, Largillière J, Coste F, Culard F, Landon C, Castaing B, Delmas AF, Paquet F. New protein-DNA complexes in archaea: a small monomeric protein induces a sharp V-turn DNA structure. Sci Rep 2019; 9:14253. [PMID: 31582767 PMCID: PMC6776556 DOI: 10.1038/s41598-019-50211-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 09/05/2019] [Indexed: 01/02/2023] Open
Abstract
MC1, a monomeric nucleoid-associated protein (NAP), is structurally unrelated to other DNA-binding proteins. The protein participates in the genome organization of several Euryarchaea species through an atypical compaction mechanism. It is also involved in DNA transcription and cellular division through unknown mechanisms. We determined the 3D solution structure of a new DNA-protein complex formed by MC1 and a strongly distorted 15 base pairs DNA. While the protein just needs to adapt its conformation slightly, the DNA undergoes a dramatic curvature (the first two bend angles of 55° and 70°, respectively) and an impressive torsional stress (dihedral angle of 106°) due to several kinks upon binding of MC1 to its concave side. Thus, it adopts a V-turn structure. For longer DNAs, MC1 stabilizes multiple V-turn conformations in a flexible and dynamic manner. The existence of such V-turn conformations of the MC1-DNA complexes leads us to propose two binding modes of the protein, as a bender (primary binding mode) and as a wrapper (secondary binding mode). Moreover, it opens up new opportunities for studying and understanding the repair, replication and transcription molecular machineries of Archaea.
Collapse
Affiliation(s)
- Karine Loth
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France. .,UFR Collegium Sciences et Techniques, Université d'Orléans, rue de Chartres, 45100, Orléans, France.
| | - Justine Largillière
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France
| | - Franck Coste
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France
| | - Françoise Culard
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France
| | - Céline Landon
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France
| | - Bertrand Castaing
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France
| | - Agnès F Delmas
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France
| | - Françoise Paquet
- Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique UPR 4301, rue Charles Sadron, F-45071, Orléans, Cedex 2, France.
| |
Collapse
|
21
|
Kutnowski N, Shmulevich F, Davidov G, Shahar A, Bar-Zvi D, Eichler J, Zarivach R, Shaanan B. Specificity of protein-DNA interactions in hypersaline environment: structural studies on complexes of Halobacterium salinarum oxidative stress-dependent protein hsRosR. Nucleic Acids Res 2019; 47:8860-8873. [PMID: 31310308 PMCID: PMC7145548 DOI: 10.1093/nar/gkz604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/13/2019] [Accepted: 07/02/2019] [Indexed: 12/21/2022] Open
Abstract
Interactions between proteins and DNA are crucial for all biological systems. Many studies have shown the dependence of protein–DNA interactions on the surrounding salt concentration. How these interactions are maintained in the hypersaline environments that halophiles inhabit remains puzzling. Towards solving this enigma, we identified the DNA motif recognized by the Halobactrium salinarum ROS-dependent transcription factor (hsRosR), determined the structure of several hsRosR–DNA complexes and investigated the DNA-binding process under extreme high-salt conditions. The picture that emerges from this work contributes to our understanding of the principles underlying the interplay between electrostatic interactions and salt-mediated protein–DNA interactions in an ionic environment characterized by molar salt concentrations.
Collapse
Affiliation(s)
- Nitzan Kutnowski
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel
| | - Fania Shmulevich
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel
| | - Geula Davidov
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel.,National Institute of Biotechnology in the Negev, Ben-Gurion University, Beer Sheva 8410510, Israel
| | - Anat Shahar
- Macromolecular Crystallography Research Center, National Institute of Biotechnology in the Negev, Ben-Gurion University, Beer Sheva 8410510, Israel
| | - Dudy Bar-Zvi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel
| | - Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel
| | - Raz Zarivach
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel.,National Institute of Biotechnology in the Negev, Ben-Gurion University, Beer Sheva 8410510, Israel
| | - Boaz Shaanan
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410510, Israel
| |
Collapse
|
22
|
Hancock SP, Cascio D, Johnson RC. Cooperative DNA binding by proteins through DNA shape complementarity. Nucleic Acids Res 2019; 47:8874-8887. [PMID: 31616952 PMCID: PMC7145599 DOI: 10.1093/nar/gkz642] [Citation(s) in RCA: 10] [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: 05/29/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 01/13/2023] Open
Abstract
Localized arrays of proteins cooperatively assemble onto chromosomes to control DNA activity in many contexts. Binding cooperativity is often mediated by specific protein-protein interactions, but cooperativity through DNA structure is becoming increasingly recognized as an additional mechanism. During the site-specific DNA recombination reaction that excises phage λ from the chromosome, the bacterial DNA architectural protein Fis recruits multiple λ-encoded Xis proteins to the attR recombination site. Here, we report X-ray crystal structures of DNA complexes containing Fis + Xis, which show little, if any, contacts between the two proteins. Comparisons with structures of DNA complexes containing only Fis or Xis, together with mutant protein and DNA binding studies, support a mechanism for cooperative protein binding solely by DNA allostery. Fis binding both molds the minor groove to potentiate insertion of the Xis β-hairpin wing motif and bends the DNA to facilitate Xis-DNA contacts within the major groove. The Fis-structured minor groove shape that is optimized for Xis binding requires a precisely positioned pyrimidine-purine base-pair step, whose location has been shown to modulate minor groove widths in Fis-bound complexes to different DNA targets.
Collapse
MESH Headings
- Allosteric Site
- Bacteriophage lambda/genetics
- Bacteriophage lambda/metabolism
- Base Sequence
- Binding Sites
- Chromosomes, Bacterial/chemistry
- Chromosomes, Bacterial/metabolism
- Cloning, Molecular
- Crystallography, X-Ray
- DNA Nucleotidyltransferases/chemistry
- DNA Nucleotidyltransferases/genetics
- DNA Nucleotidyltransferases/metabolism
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Escherichia coli Proteins/chemistry
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/metabolism
- Factor For Inversion Stimulation Protein/chemistry
- Factor For Inversion Stimulation Protein/genetics
- Factor For Inversion Stimulation Protein/metabolism
- Gene Expression
- Genetic Vectors/chemistry
- Genetic Vectors/metabolism
- Kinetics
- Models, Molecular
- Nucleic Acid Conformation
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Recombinational DNA Repair
- Sequence Alignment
- Thermodynamics
- Viral Proteins/chemistry
- Viral Proteins/genetics
- Viral Proteins/metabolism
Collapse
Affiliation(s)
- Stephen P Hancock
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
- Department of Chemistry, Towson University, 8000 York Rd., Towson, MD 21252, USA
| | - Duilio Cascio
- University of California at Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California at Los Angeles, Los Angeles, CA 90095-1570, USA
| | - Reid C Johnson
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
23
|
Sagendorf JM, Berman HM, Rohs R. DNAproDB: an interactive tool for structural analysis of DNA-protein complexes. Nucleic Acids Res 2019; 45:W89-W97. [PMID: 28431131 PMCID: PMC5570235 DOI: 10.1093/nar/gkx272] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/06/2017] [Indexed: 02/06/2023] Open
Abstract
Many biological processes are mediated by complex interactions between DNA and proteins. Transcription factors, various polymerases, nucleases and histones recognize and bind DNA with different levels of binding specificity. To understand the physical mechanisms that allow proteins to recognize DNA and achieve their biological functions, it is important to analyze structures of DNA–protein complexes in detail. DNAproDB is a web-based interactive tool designed to help researchers study these complexes. DNAproDB provides an automated structure-processing pipeline that extracts structural features from DNA–protein complexes. The extracted features are organized in structured data files, which are easily parsed with any programming language or viewed in a browser. We processed a large number of DNA–protein complexes retrieved from the Protein Data Bank and created the DNAproDB database to store this data. Users can search the database by combining features of the DNA, protein or DNA–protein interactions at the interface. Additionally, users can upload their own structures for processing privately and securely. DNAproDB provides several interactive and customizable tools for creating visualizations of the DNA–protein interface at different levels of abstraction that can be exported as high quality figures. All functionality is documented and freely accessible at http://dnaprodb.usc.edu.
Collapse
Affiliation(s)
- Jared M Sagendorf
- Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Helen M Berman
- RCSB Protein Data Bank, Center for Integrative Proteomics Research, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Remo Rohs
- Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
24
|
Lai X, Stigliani A, Vachon G, Carles C, Smaczniak C, Zubieta C, Kaufmann K, Parcy F. Building Transcription Factor Binding Site Models to Understand Gene Regulation in Plants. MOLECULAR PLANT 2019; 12:743-763. [PMID: 30447332 DOI: 10.1016/j.molp.2018.10.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/20/2018] [Accepted: 10/30/2018] [Indexed: 06/09/2023]
Abstract
Transcription factors (TFs) are key cellular components that control gene expression. They recognize specific DNA sequences, the TF binding sites (TFBSs), and thus are targeted to specific regions of the genome where they can recruit transcriptional co-factors and/or chromatin regulators to fine-tune spatiotemporal gene regulation. Therefore, the identification of TFBSs in genomic sequences and their subsequent quantitative modeling is of crucial importance for understanding and predicting gene expression. Here, we review how TFBSs can be determined experimentally, how the TFBS models can be constructed in silico, and how they can be optimized by taking into account features such as position interdependence within TFBSs, DNA shape, and/or by introducing state-of-the-art computational algorithms such as deep learning methods. In addition, we discuss the integration of context variables into the TFBS modeling, including nucleosome positioning, chromatin states, methylation patterns, 3D genome architectures, and TF cooperative binding, in order to better predict TF binding under cellular contexts. Finally, we explore the possibilities of combining the optimized TFBS model with technological advances, such as targeted TFBS perturbation by CRISPR, to better understand gene regulation, evolution, and plant diversity.
Collapse
Affiliation(s)
- Xuelei Lai
- CNRS, Univ. Grenoble Alpes, CEA, INRA, BIG-LPCV, 38000 Grenoble, France.
| | - Arnaud Stigliani
- CNRS, Univ. Grenoble Alpes, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Gilles Vachon
- CNRS, Univ. Grenoble Alpes, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Cristel Carles
- CNRS, Univ. Grenoble Alpes, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Cezary Smaczniak
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Chloe Zubieta
- CNRS, Univ. Grenoble Alpes, CEA, INRA, BIG-LPCV, 38000 Grenoble, France
| | - Kerstin Kaufmann
- Department for Plant Cell and Molecular Biology, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - François Parcy
- CNRS, Univ. Grenoble Alpes, CEA, INRA, BIG-LPCV, 38000 Grenoble, France.
| |
Collapse
|
25
|
Zavyalova E, Kopylov A. Energy Transfer as A Driving Force in Nucleic Acid⁻Protein Interactions. Molecules 2019; 24:molecules24071443. [PMID: 30979095 PMCID: PMC6480146 DOI: 10.3390/molecules24071443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/10/2019] [Accepted: 04/11/2019] [Indexed: 12/19/2022] Open
Abstract
Many nucleic acid–protein structures have been resolved, though quantitative structure-activity relationship remains unclear in many cases. Thrombin complexes with G-quadruplex aptamers are striking examples of a lack of any correlation between affinity, interface organization, and other common parameters. Here, we tested the hypothesis that affinity of the aptamer–protein complex is determined with the capacity of the interface to dissipate energy of binding. Description and detailed analysis of 63 nucleic acid–protein structures discriminated peculiarities of high-affinity nucleic acid–protein complexes. The size of the amino acid sidechain in the interface was demonstrated to be the most significant parameter that correlates with affinity of aptamers. This observation could be explained in terms of need of efficient energy transfer from interacting residues. Application of energy dissipation theory provided an illustrative tool for estimation of efficiency of aptamer–protein complexes. These results are of great importance for a design of efficient aptamers.
Collapse
Affiliation(s)
| | - Alexey Kopylov
- Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia.
| |
Collapse
|
26
|
Abstract
Allosteric interactions in DNA are crucial for various biological processes. These interactions are quantified by measuring the change in free energy as a function of the distance between the binding sites for two ligands. Here, we show that trends in the interaction energy of ligands binding to DNA can be explained within an elastic birod model, which accounts for the deformation of each strand as well as the change in stacking energy due to perturbations in position and orientation of the bases caused by the binding of ligands. The strain fields produced by the ligands decay with distance from the binding site. The interaction energy of two ligands decays exponentially with the distance between them and oscillates with the periodicity of the double helix in quantitative agreement with experimental measurements. The trend in the computed interaction energy is similar to that in the perturbation of groove width produced by the binding of a single ligand, which is consistent with molecular simulations. Our analysis provides a new framework to understand allosteric interactions in DNA and can be extended to other rod-like macromolecules whose elasticity plays a role in biological functions.
Collapse
Affiliation(s)
- Jaspreet Singh
- Department of Mechanical Engineering and Applied Mechanics , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Prashant K Purohit
- Department of Mechanical Engineering and Applied Mechanics , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| |
Collapse
|
27
|
Post-translational modification of nucleoid-associated proteins: an extra layer of functional modulation in bacteria? Biochem Soc Trans 2018; 46:1381-1392. [PMID: 30287510 DOI: 10.1042/bst20180488] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/31/2018] [Accepted: 09/04/2018] [Indexed: 01/08/2023]
Abstract
Post-translational modification (PTM) of histones has been investigated in eukaryotes for years, revealing its widespread occurrence and functional importance. Many PTMs affect chromatin folding and gene activity. Only recently the occurrence of such modifications has been recognized in bacteria. However, it is unclear whether PTM of the bacterial counterparts of eukaryotic histones, nucleoid-associated proteins (NAPs), bears a comparable significance. Here, we scrutinize proteome mass spectrometry data for PTMs of the four most abundantly present NAPs in Escherichia coli (H-NS, HU, IHF and FIS). This approach allowed us to identify a total of 101 unique PTMs in the 11 independent proteomic studies covered in this review. Combined with structural and genetic information on these proteins, we describe potential effects of these modifications (perturbed DNA-binding, structural integrity or interaction with other proteins) on their function.
Collapse
|
28
|
Singh J, Purohit PK. Allosteric interactions in a birod model of DNA. Proc Math Phys Eng Sci 2018; 474:20180136. [PMID: 34025206 PMCID: PMC6237492 DOI: 10.1098/rspa.2018.0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 09/05/2018] [Indexed: 06/12/2023] Open
Abstract
Allosteric interactions between molecules bound to DNA at distant locations have been known for a long time. The phenomenon has been studied via experiments and numerical simulations, but a comprehensive understanding grounded in a theory of DNA elasticity remains a challenge. Here, we quantify allosteric interactions between two entities bound to DNA by using the theory of birods. We recognize that molecules bound to DNA cause local deformations that can be captured in a birod model which consists of two elastic strands interacting via an elastic web representing the basepairs. We show that the displacement field caused by bound entities decays exponentially with distance from the binding site. We compute the interaction energy between two proteins on DNA as a function of distance between them and find that it decays exponentially while oscillating with the periodicity of the double helix, in excellent agreement with experiments. The decay length of the interaction energy can be determined in terms of the mechanical properties of the strands and the webbing in our birod model, and it varies with the GC content of the DNA. Our model provides a framework for viewing allosteric interactions in DNA within the ambit of configurational forces of continuum elasticity.
Collapse
|
29
|
Käppel S, Melzer R, Rümpler F, Gafert C, Theißen G. The floral homeotic protein SEPALLATA3 recognizes target DNA sequences by shape readout involving a conserved arginine residue in the MADS-domain. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 95:341-357. [PMID: 29744943 DOI: 10.1111/tpj.13954] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/17/2018] [Accepted: 04/23/2018] [Indexed: 05/05/2023]
Abstract
SEPALLATA3 of Arabidopsis thaliana is a MADS-domain transcription factor (TF) and a key regulator of flower development. MADS-domain proteins bind to sequences termed 'CArG-boxes' [consensus 5'-CC(A/T)6 GG-3']. Because only a fraction of the CArG-boxes in the Arabidopsis genome are bound by SEPALLATA3, more elaborate principles have to be discovered to better understand which features turn CArG-boxes into genuine recognition sites. Here, we investigate to what extent the shape of the DNA is involved in a 'shape readout' that contributes to the binding of SEPALLATA3. We determined in vitro binding affinities of SEPALLATA3 to DNA probes that all contain the CArG-box motif, but differ in their predicted DNA shape. We found that binding affinity correlates well with a narrow minor groove of the DNA. Substitution of canonical bases with non-standard bases supports the hypothesis of minor groove shape readout by SEPALLATA3. Analysis of mutant SEPALLATA3 proteins further revealed that a highly conserved arginine residue, which is expected to contact the DNA minor groove, contributes significantly to the shape readout. Our studies show that the specific recognition of cis-regulatory elements by a plant MADS-domain TF, and by inference probably also of other TFs of this type, heavily depends on shape readout mechanisms.
Collapse
Affiliation(s)
- Sandra Käppel
- Department of Genetics, Friedrich Schiller University Jena, Philosophenweg 12, D-07743, Jena, Germany
| | - Rainer Melzer
- Department of Genetics, Friedrich Schiller University Jena, Philosophenweg 12, D-07743, Jena, Germany
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Florian Rümpler
- Department of Genetics, Friedrich Schiller University Jena, Philosophenweg 12, D-07743, Jena, Germany
| | - Christian Gafert
- Department of Genetics, Friedrich Schiller University Jena, Philosophenweg 12, D-07743, Jena, Germany
| | - Günter Theißen
- Department of Genetics, Friedrich Schiller University Jena, Philosophenweg 12, D-07743, Jena, Germany
| |
Collapse
|
30
|
Dahlke K, Sing CE. Force-extension behavior of DNA in the presence of DNA-bending nucleoid associated proteins. J Chem Phys 2018; 148:084902. [PMID: 29495783 DOI: 10.1063/1.5016177] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Interactions between nucleoid associated proteins (NAPs) and DNA affect DNA polymer conformation, leading to phenomena such as concentration dependent force-extension behavior. These effects, in turn, also impact the local binding behavior of the protein, such as high forces causing proteins to unbind, or proteins binding favorably to locally bent DNA. We develop a coarse-grained NAP-DNA simulation model that incorporates both force- and concentration-dependent behaviors, in order to study the interplay between NAP binding and DNA conformation. This model system includes multi-state protein binding and unbinding, motivated by prior work, but is now dependent on the local structure of the DNA, which is related to external forces acting on the DNA strand. We observe the expected qualitative binding behavior, where more proteins are bound at lower forces than at higher forces. Our model also includes NAP-induced DNA bending, which affects DNA elasticity. We see semi-quantitative matching of our simulated force-extension behavior to the reported experimental data. By using a coarse-grained simulation, we are also able to look at non-equilibrium behaviors, such as dynamic extension of a DNA strand. We stretch a DNA strand at different rates and at different NAP concentrations to observe how the time scales of the system (such as pulling time and unbinding time) work in concert. When these time scales are similar, we observe measurable rate-dependent changes in the system, which include the number of proteins bound and the force required to extend the DNA molecule. This suggests that the relative time scales of different dynamic processes play an important role in the behavior of NAP-DNA systems.
Collapse
Affiliation(s)
- K Dahlke
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - C E Sing
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| |
Collapse
|
31
|
Paul A, Kumar A, Nanjunda R, Farahat AA, Boykin DW, Wilson WD. Systematic synthetic and biophysical development of mixed sequence DNA binding agents. Org Biomol Chem 2018; 15:827-835. [PMID: 27995240 DOI: 10.1039/c6ob02390h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It is now well established that, although only about 5% of the human genome codes for protein, most of the DNA has some function, such as synthesis of specific, functional RNAs and/or control of gene expression. These functional sequences open immense possibilities in both biotechnology and therapeutics for the use of cell-permeable, small molecules that can bind mixed-base pair sequences of DNA for regulation of genomic functions. Unfortunately very few types of modules have been designed to recognize mixed DNA sequences and for progress in targeting specific genes, it is essential to have additional classes of compounds. Compounds that can be rationally designed from established modules and which can bind strongly to mixed base pair DNA sequences are especially attractive. Based on extensive experience in design of minor-groove agents for AT recognition, a small library of compounds with two AT specific binding modules, connected through linkers which can recognize the G·C base pairs, were prepared. The compound-DNA interactions were evaluated with a powerful array of biophysical methods and the results show that some pyridyl-linked compounds bind with the target sequence with sub-nanomolar KD, with very slow dissociation kinetics and 200 times selectivity over the related sequence without a G·C base pair. Interestingly, a set of compounds with AT module connected by different linkers shows cooperative dimer recognition of related sequences. This type of design approach can be expanded to additional modules for recognition of a wide variety of sequences.
Collapse
Affiliation(s)
- Ananya Paul
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| | - Arvind Kumar
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| | - Rupesh Nanjunda
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA. and Janssen Research and Development, 1400 McKean Rd, Spring House, PA 19477, USA
| | - Abdelbasset A Farahat
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA. and Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - David W Boykin
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| | - W David Wilson
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303-3083, USA.
| |
Collapse
|
32
|
Rube HT, Rastogi C, Kribelbauer JF, Bussemaker HJ. A unified approach for quantifying and interpreting DNA shape readout by transcription factors. Mol Syst Biol 2018; 14:e7902. [PMID: 29472273 PMCID: PMC5822049 DOI: 10.15252/msb.20177902] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 01/26/2018] [Accepted: 01/31/2018] [Indexed: 01/07/2023] Open
Abstract
Transcription factors (TFs) interpret DNA sequence by probing the chemical and structural properties of the nucleotide polymer. DNA shape is thought to enable a parsimonious representation of dependencies between nucleotide positions. Here, we propose a unified mathematical representation of the DNA sequence dependence of shape and TF binding, respectively, which simplifies and enhances analysis of shape readout. First, we demonstrate that linear models based on mononucleotide features alone account for 60-70% of the variance in minor groove width, roll, helix twist, and propeller twist. This explains why simple scoring matrices that ignore all dependencies between nucleotide positions can partially account for DNA shape readout by a TF Adding dinucleotide features as sequence-to-shape predictors to our model, we can almost perfectly explain the shape parameters. Building on this observation, we developed a post hoc analysis method that can be used to analyze any mechanism-agnostic protein-DNA binding model in terms of shape readout. Our insights provide an alternative strategy for using DNA shape information to enhance our understanding of how cis-regulatory codes are interpreted by the cellular machinery.
Collapse
Affiliation(s)
- H Tomas Rube
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Chaitanya Rastogi
- Department of Biological Sciences, Columbia University, New York, NY, USA
- Program in Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
| | - Judith F Kribelbauer
- Department of Biological Sciences, Columbia University, New York, NY, USA
- Department of Systems Biology, Columbia University Medical Center, New York, NY, USA
| | - Harmen J Bussemaker
- Department of Biological Sciences, Columbia University, New York, NY, USA
- Department of Systems Biology, Columbia University Medical Center, New York, NY, USA
| |
Collapse
|
33
|
Kamagata K, Mano E, Ouchi K, Kanbayashi S, Johnson RC. High Free-Energy Barrier of 1D Diffusion Along DNA by Architectural DNA-Binding Proteins. J Mol Biol 2018; 430:655-667. [PMID: 29307468 DOI: 10.1016/j.jmb.2018.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/13/2017] [Accepted: 01/02/2018] [Indexed: 01/25/2023]
Abstract
Architectural DNA-binding proteins function to regulate diverse DNA reactions and have the defining property of significantly changing DNA conformation. Although the 1D movement along DNA by other types of DNA-binding proteins has been visualized, the mobility of architectural DNA-binding proteins on DNA remains unknown. Here, we applied single-molecule fluorescence imaging on arrays of extended DNA molecules to probe the binding dynamics of three structurally distinct architectural DNA-binding proteins: Nhp6A, HU, and Fis. Each of these proteins was observed to move along DNA, and the salt concentration independence of the 1D diffusion implies sliding with continuous contact to DNA. Nhp6A and HU exhibit a single sliding mode, whereas Fis exhibits two sliding modes. Based on comparison of the diffusion coefficients and sizes of many DNA binding proteins, the architectural proteins are categorized into a new group distinguished by an unusually high free-energy barrier for 1D diffusion. The higher free-energy barrier for 1D diffusion by architectural proteins can be attributed to the large DNA conformational changes that accompany binding and impede rotation-coupled movement along the DNA grooves.
Collapse
Affiliation(s)
- Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan; Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Aoba-ku, Sendai980-8577, Japan.
| | - Eriko Mano
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Kana Ouchi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan; Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Aoba-ku, Sendai980-8577, Japan
| | - Saori Kanbayashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Reid C Johnson
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA90095-1737, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| |
Collapse
|
34
|
Chiu TP, Rao S, Mann RS, Honig B, Rohs R. Genome-wide prediction of minor-groove electrostatic potential enables biophysical modeling of protein-DNA binding. Nucleic Acids Res 2017; 45:12565-12576. [PMID: 29040720 PMCID: PMC5716191 DOI: 10.1093/nar/gkx915] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 09/28/2017] [Indexed: 12/16/2022] Open
Abstract
Protein–DNA binding is a fundamental component of gene regulatory processes, but it is still not completely understood how proteins recognize their target sites in the genome. Besides hydrogen bonding in the major groove (base readout), proteins recognize minor-groove geometry using positively charged amino acids (shape readout). The underlying mechanism of DNA shape readout involves the correlation between minor-groove width and electrostatic potential (EP). To probe this biophysical effect directly, rather than using minor-groove width as an indirect measure for shape readout, we developed a methodology, DNAphi, for predicting EP in the minor groove and confirmed the direct role of EP in protein–DNA binding using massive sequencing data. The DNAphi method uses a sliding-window approach to mine results from non-linear Poisson–Boltzmann (NLPB) calculations on DNA structures derived from all-atom Monte Carlo simulations. We validated this approach, which only requires nucleotide sequence as input, based on direct comparison with NLPB calculations for available crystal structures. Using statistical machine-learning approaches, we showed that adding EP as a biophysical feature can improve the predictive power of quantitative binding specificity models across 27 transcription factor families. High-throughput prediction of EP offers a novel way to integrate biophysical and genomic studies of protein–DNA binding.
Collapse
Affiliation(s)
- Tsu-Pei Chiu
- Computational Biology and Bioinformatics Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Satyanarayan Rao
- Computational Biology and Bioinformatics Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Richard S Mann
- Departments of Systems Biology and Biochemistry & Molecular Biophysics, Mortimer B. Zuckerman Institute, Columbia University, New York, NY 10032, USA
| | - Barry Honig
- Departments of Systems Biology and Biochemistry & Molecular Biophysics, Mortimer B. Zuckerman Institute, Columbia University, New York, NY 10032, USA.,Howard Hughes Medical Institute, New York, NY 10032, USA
| | - Remo Rohs
- Computational Biology and Bioinformatics Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
35
|
Abadi S, Yan WX, Amar D, Mayrose I. A machine learning approach for predicting CRISPR-Cas9 cleavage efficiencies and patterns underlying its mechanism of action. PLoS Comput Biol 2017; 13:e1005807. [PMID: 29036168 PMCID: PMC5658169 DOI: 10.1371/journal.pcbi.1005807] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 10/26/2017] [Accepted: 10/02/2017] [Indexed: 12/21/2022] Open
Abstract
The adaptation of the CRISPR-Cas9 system as a genome editing technique has generated much excitement in recent years owing to its ability to manipulate targeted genes and genomic regions that are complementary to a programmed single guide RNA (sgRNA). However, the efficacy of a specific sgRNA is not uniquely defined by exact sequence homology to the target site, thus unintended off-targets might additionally be cleaved. Current methods for sgRNA design are mainly concerned with predicting off-targets for a given sgRNA using basic sequence features and employ elementary rules for ranking possible sgRNAs. Here, we introduce CRISTA (CRISPR Target Assessment), a novel algorithm within the machine learning framework that determines the propensity of a genomic site to be cleaved by a given sgRNA. We show that the predictions made with CRISTA are more accurate than other available methodologies. We further demonstrate that the occurrence of bulges is not a rare phenomenon and should be accounted for in the prediction process. Beyond predicting cleavage efficiencies, the learning process provides inferences regarding patterns that underlie the mechanism of action of the CRISPR-Cas9 system. We discover that attributes that describe the spatial structure and rigidity of the entire genomic site as well as those surrounding the PAM region are a major component of the prediction capabilities.
Collapse
Affiliation(s)
- Shiran Abadi
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, Israel
| | - Winston X. Yan
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Graduate Program in Biophysics, Harvard Medical School, Boston, Massachusetts, United States of America
- Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David Amar
- Blavatnik School of Computer Science, Tel-Aviv University, Tel Aviv, Israel
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, United States of America
| | - Itay Mayrose
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
36
|
Structure-function analysis of the DNA-binding domain of a transmembrane transcriptional activator. Sci Rep 2017; 7:1051. [PMID: 28432336 PMCID: PMC5430869 DOI: 10.1038/s41598-017-01031-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/23/2017] [Indexed: 11/08/2022] Open
Abstract
The transmembrane DNA-binding protein CadC of E. coli, a representative of the ToxR-like receptor family, combines input and effector domains for signal sensing and transcriptional activation, respectively, in a single protein, thus representing one of the simplest signalling systems. At acidic pH in a lysine-rich environment, CadC activates the transcription of the cadBA operon through recruitment of the RNA polymerase (RNAP) to the two cadBA promoter sites, Cad1 and Cad2, which are directly bound by CadC. However, the molecular details for its interaction with DNA have remained elusive. Here, we present the crystal structure of the CadC DNA-binding domain (DBD) and show that it adopts a winged helix-turn-helix fold. The interaction with the cadBA promoter site Cad1 is studied by using nuclear magnetic resonance (NMR) spectroscopy, biophysical methods and functional assays and reveals a preference for AT-rich regions. By mutational analysis we identify amino acids within the CadC DBD that are crucial for DNA-binding and functional activity. Experimentally derived structural models of the CadC-DNA complex indicate that the CadC DBD employs mainly non-sequence-specific over a few specific contacts. Our data provide molecular insights into the CadC-DNA interaction and suggest how CadC dimerization may provide high-affinity binding to the Cad1 promoter.
Collapse
|
37
|
Chen C, Pettitt BM. DNA Shape versus Sequence Variations in the Protein Binding Process. Biophys J 2017; 110:534-544. [PMID: 26840719 DOI: 10.1016/j.bpj.2015.11.3527] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/15/2015] [Accepted: 11/02/2015] [Indexed: 01/02/2023] Open
Abstract
The binding process of a protein with a DNA involves three stages: approach, encounter, and association. It has been known that the complexation of protein and DNA involves mutual conformational changes, especially for a specific sequence association. However, it is still unclear how the conformation and the information in the DNA sequences affects the binding process. What is the extent to which the DNA structure adopted in the complex is induced by protein binding, or is instead intrinsic to the DNA sequence? In this study, we used the multiscale simulation method to explore the binding process of a protein with DNA in terms of DNA sequence, conformation, and interactions. We found that in the approach stage the protein can bind both the major and minor groove of the DNA, but uses different features to locate the binding site. The intrinsic conformational properties of the DNA play a significant role in this binding stage. By comparing the specific DNA with the nonspecific in unbound, intermediate, and associated states, we found that for a specific DNA sequence, ∼40% of the bending in the association forms is intrinsic and that ∼60% is induced by the protein. The protein does not induce appreciable bending of nonspecific DNA. In addition, we proposed that the DNA shape variations induced by protein binding are required in the early stage of the binding process, so that the protein is able to approach, encounter, and form an intermediate at the correct site on DNA.
Collapse
Affiliation(s)
- Chuanying Chen
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas
| | - B Montgomery Pettitt
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas.
| |
Collapse
|
38
|
Sharmin M, Bravo HC, Hannenhalli S. Heterogeneity of transcription factor binding specificity models within and across cell lines. Genome Res 2016; 26:1110-23. [PMID: 27311443 PMCID: PMC4971765 DOI: 10.1101/gr.199166.115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 06/16/2016] [Indexed: 12/24/2022]
Abstract
Complex gene expression patterns are mediated by the binding of transcription factors (TFs) to specific genomic loci. The in vivo occupancy of a TF is, in large part, determined by the TF's DNA binding interaction partners, motivating genomic context-based models of TF occupancy. However, approaches thus far have assumed a uniform TF binding model to explain genome-wide cell-type–specific binding sites. Therefore, the cell type heterogeneity of TF occupancy models, as well as the extent to which binding rules underlying a TF's occupancy are shared across cell types, has not been investigated. Here, we develop an ensemble-based approach (TRISECT) to identify the heterogeneous binding rules for cell-type–specific TF occupancy and analyze the inter-cell-type sharing of such rules. Comprehensive analysis of 23 TFs, each with ChIP-seq data in four to 12 different cell types, shows that by explicitly capturing the heterogeneity of binding rules, TRISECT accurately identifies in vivo TF occupancy. Importantly, many of the binding rules derived from individual cell types are shared across cell types and reveal distinct yet functionally coherent putative target genes in different cell types. Closer inspection of the predicted cell-type–specific interaction partners provides insights into the context-specific functional landscape of a TF. Together, our novel ensemble-based approach reveals, for the first time, a widespread heterogeneity of binding rules, comprising the interaction partners within a cell type, many of which nevertheless transcend cell types. Notably, the putative targets of shared binding rules in different cell types, while distinct, exhibit significant functional coherence.
Collapse
Affiliation(s)
- Mahfuza Sharmin
- Department of Computer Science, University of Maryland, College Park, Maryland 20742, USA; Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland 20742, USA
| | - Héctor Corrada Bravo
- Department of Computer Science, University of Maryland, College Park, Maryland 20742, USA; Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland 20742, USA
| | - Sridhar Hannenhalli
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland 20742, USA; Department of Cell and Molecular Biology, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
39
|
Dror I, Rohs R, Mandel-Gutfreund Y. How motif environment influences transcription factor search dynamics: Finding a needle in a haystack. Bioessays 2016; 38:605-12. [PMID: 27192961 PMCID: PMC5023137 DOI: 10.1002/bies.201600005] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transcription factors (TFs) have to find their binding sites, which are distributed throughout the genome. Facilitated diffusion is currently the most widely accepted model for this search process. Based on this model the TF alternates between one-dimensional sliding along the DNA, and three-dimensional bulk diffusion. In this view, the non-specific associations between the proteins and the DNA play a major role in the search dynamics. However, little is known about how the DNA properties around the motif contribute to the search. Accumulating evidence showing that TF binding sites are embedded within a unique environment, specific to each TF, leads to the hypothesis that the search process is facilitated by favorable DNA features that help to improve the search efficiency. Here, we review the field and present the hypothesis that TF-DNA recognition is dictated not only by the motif, but is also influenced by the environment in which the motif resides.
Collapse
Affiliation(s)
- Iris Dror
- Department of Biology, Technion - Israel Institute of Technology, Technion City, Haifa, Israel.,Departments of Biological Sciences, Chemistry, Physics, and Computer Science, Molecular and Computational Biology Program, University of Southern California, Los Angeles, CA, USA
| | - Remo Rohs
- Departments of Biological Sciences, Chemistry, Physics, and Computer Science, Molecular and Computational Biology Program, University of Southern California, Los Angeles, CA, USA
| | - Yael Mandel-Gutfreund
- Department of Biology, Technion - Israel Institute of Technology, Technion City, Haifa, Israel
| |
Collapse
|
40
|
Abstract
The site-specific recombinase encoded by bacteriophage λ (Int) is responsible for integrating and excising the viral chromosome into and out of the chromosome of its Escherichia coli host. Int carries out a reaction that is highly directional, tightly regulated, and depends upon an ensemble of accessory DNA bending proteins acting on 240 bp of DNA encoding 16 protein binding sites. This additional complexity enables two pathways, integrative and excisive recombination, whose opposite, and effectively irreversible, directions are dictated by different physiological and environmental signals. Int recombinase is a heterobivalent DNA binding protein and each of the four Int protomers, within a multiprotein 400 kDa recombinogenic complex, is thought to bind and, with the aid of DNA bending proteins, bridge one arm- and one core-type DNA site. In the 12 years since the publication of the last review focused solely on the λ site-specific recombination pathway in Mobile DNA II, there has been a great deal of progress in elucidating the molecular details of this pathway. The most dramatic advances in our understanding of the reaction have been in the area of X-ray crystallography where protein-DNA structures have now been determined for of all of the DNA-protein interfaces driving the Int pathway. Building on this foundation of structures, it has been possible to derive models for the assembly of components that determine the regulatory apparatus in the P-arm, and for the overall architectures that define excisive and integrative recombinogenic complexes. The most fundamental additional mechanistic insights derive from the application of hexapeptide inhibitors and single molecule kinetics.
Collapse
|
41
|
Hancock SP, Stella S, Cascio D, Johnson RC. DNA Sequence Determinants Controlling Affinity, Stability and Shape of DNA Complexes Bound by the Nucleoid Protein Fis. PLoS One 2016; 11:e0150189. [PMID: 26959646 PMCID: PMC4784862 DOI: 10.1371/journal.pone.0150189] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 01/28/2016] [Indexed: 11/18/2022] Open
Abstract
The abundant Fis nucleoid protein selectively binds poorly related DNA sequences with high affinities to regulate diverse DNA reactions. Fis binds DNA primarily through DNA backbone contacts and selects target sites by reading conformational properties of DNA sequences, most prominently intrinsic minor groove widths. High-affinity binding requires Fis-stabilized DNA conformational changes that vary depending on DNA sequence. In order to better understand the molecular basis for high affinity site recognition, we analyzed the effects of DNA sequence within and flanking the core Fis binding site on binding affinity and DNA structure. X-ray crystal structures of Fis-DNA complexes containing variable sequences in the noncontacted center of the binding site or variations within the major groove interfaces show that the DNA can adapt to the Fis dimer surface asymmetrically. We show that the presence and position of pyrimidine-purine base steps within the major groove interfaces affect both local DNA bending and minor groove compression to modulate affinities and lifetimes of Fis-DNA complexes. Sequences flanking the core binding site also modulate complex affinities, lifetimes, and the degree of local and global Fis-induced DNA bending. In particular, a G immediately upstream of the 15 bp core sequence inhibits binding and bending, and A-tracts within the flanking base pairs increase both complex lifetimes and global DNA curvatures. Taken together, our observations support a revised DNA motif specifying high-affinity Fis binding and highlight the range of conformations that Fis-bound DNA can adopt. The affinities and DNA conformations of individual Fis-DNA complexes are likely to be tailored to their context-specific biological functions.
Collapse
Affiliation(s)
- Stephen P. Hancock
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
| | - Stefano Stella
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
| | - Duilio Cascio
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
- Department of Energy Institute of Genomics and Proteomics, University of California at Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Reid C. Johnson
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
42
|
Stellwagen E, Dong Q, Stellwagen NC. Flanking A·T basepairs destabilize the B(∗) conformation of DNA A-tracts. Biophys J 2016; 108:2291-9. [PMID: 25954886 DOI: 10.1016/j.bpj.2015.01.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 01/17/2015] [Accepted: 01/26/2015] [Indexed: 11/25/2022] Open
Abstract
Capillary electrophoresis has been used to characterize the interaction of monovalent cations with 26-basepair DNA oligomers containing A-tracts embedded in flanking sequences with different basepair compositions. A 26-basepair random-sequence oligomer was used as the reference; lithium and tetrabutylammonium (TBA(+)) ions were used as the probe ions. The free solution mobilities of the A-tract and random-sequence oligomers were identical in solutions containing <∼ 100 mM cation. At higher cation concentrations, the A-tract oligomers migrated faster than the reference oligomer in TBA(+) and slower than the reference in Li(+). Hence, cations of different sizes can interact very differently with DNA A-tracts. The increased mobilities observed in TBA(+) suggest that the large hydrophobic TBA(+) ions are preferentially excluded from the vicinity of the A-tract minor groove, increasing the effective net charge of the A-tract oligomers and increasing the mobility. By contrast, Li(+) ions decrease the mobility of A-tract oligomers because of the preferential localization of Li(+) ions in the narrow A-tract minor groove. Embedding the A-tracts in AT-rich flanking sequences markedly alters preferential interactions of monovalent cations with the B(∗) conformation. Hence, A-tracts embedded in genomic DNA may or may not interact preferentially with monovalent cations, depending on the relative number of A · T basepairs in the flanking sequences.
Collapse
Affiliation(s)
| | - Qian Dong
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa
| | | |
Collapse
|
43
|
Yang C, Chang CH. Exploring comprehensive within-motif dependence of transcription factor binding in Escherichia coli. Sci Rep 2015; 5:17021. [PMID: 26592556 PMCID: PMC4655474 DOI: 10.1038/srep17021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/16/2015] [Indexed: 01/18/2023] Open
Abstract
Modeling the binding of transcription factors helps to decipher the control logic behind transcriptional regulatory networks. Position weight matrix is commonly used to describe a binding motif but assumes statistical independence between positions. Although current approaches take within-motif dependence into account for better predictive performance, these models usually rely on prior knowledge and incorporate simple positional dependence to describe binding motifs. The inability to take complex within-motif dependence into account may result in an incomplete representation of binding motifs. In this work, we applied association rule mining techniques and constructed models to explore within-motif dependence for transcription factors in Escherichia coli. Our models can reflect transcription factor-DNA recognition where the explored dependence correlates with the binding specificity. We also propose a graphical representation of the explored within-motif dependence to illustrate the final binding configurations. Understanding the binding configurations also enables us to fine-tune or design transcription factor binding sites, and we attempt to present the configurations through exploring within-motif dependence.
Collapse
Affiliation(s)
- Chi Yang
- Institute of Biomedical Informatics, National Yang Ming University, Taipei, 11221, Taiwan
| | - Chuan-Hsiung Chang
- Institute of Biomedical Informatics, National Yang Ming University, Taipei, 11221, Taiwan.,Center for Systems and Synthetic Biology, National Yang Ming University, Taipei, 11221, Taiwan
| |
Collapse
|
44
|
Gu C, Zhang J, Yang YI, Chen X, Ge H, Sun Y, Su X, Yang L, Xie S, Gao YQ. DNA Structural Correlation in Short and Long Ranges. J Phys Chem B 2015; 119:13980-90. [PMID: 26439165 DOI: 10.1021/acs.jpcb.5b06217] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recent single-molecule measurements have revealed the DNA allostery in protein/DNA binding. MD simulations showed that this allosteric effect is associated with the deformation properties of DNA. In this study, we used MD simulations to further investigate the mechanism of DNA structural correlation, its dependence on DNA sequence, and the chemical modification of the bases. Besides a random sequence, poly d(AT) and poly d(GC) are also used as simpler model systems, which show the different bending and twisting flexibilities. The base-stacking interactions and the methyl group on the 5-carbon site of thymine causes local structures and flexibility to be very different for the two model systems, which further lead to obviously different tendencies of the conformational deformations, including the long-range allosteric effects.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Sunney Xie
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
| | | |
Collapse
|
45
|
DNA-Segment-Facilitated Dissociation of Fis and NHP6A from DNA Detected via Single-Molecule Mechanical Response. J Mol Biol 2015. [PMID: 26220077 DOI: 10.1016/j.jmb.2015.07.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rate of dissociation of a DNA-protein complex is often considered to be a property of that complex, without dependence on other nearby molecules in solution. We study the kinetics of dissociation of the abundant Escherichia coli nucleoid protein Fis from DNA, using a single-molecule mechanics assay. The rate of Fis dissociation from DNA is strongly dependent on the solution concentration of DNA. The off-rate (k(off)) of Fis from DNA shows an initially linear dependence on solution DNA concentration, characterized by an exchange rate of k(ex)≈9×10(-4) (ng/μl)(-1) s(-1) for 100 mM univalent salt buffer, with a very small off-rate at zero DNA concentration. The off-rate saturates at approximately k(off,max)≈8×10(-3) s(-1) for DNA concentrations above ≈20 ng/μl. This exchange reaction depends mainly on DNA concentration with little dependence on the length of the DNA molecules in solution or on binding affinity, but this does increase with increasing salt concentration. We also show data for the yeast HMGB protein NHP6A showing a similar DNA-concentration-dependent dissociation effect, with faster rates suggesting generally weaker DNA binding by NHP6A relative to Fis. Our results are well described by a model with an intermediate partially dissociated state where the protein is susceptible to being captured by a second DNA segment, in the manner of "direct transfer" reactions studied for other DNA-binding proteins. This type of dissociation pathway may be important to protein-DNA binding kinetics in vivo where DNA concentrations are large.
Collapse
|
46
|
Dror I, Golan T, Levy C, Rohs R, Mandel-Gutfreund Y. A widespread role of the motif environment in transcription factor binding across diverse protein families. Genome Res 2015; 25:1268-80. [PMID: 26160164 PMCID: PMC4561487 DOI: 10.1101/gr.184671.114] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 07/08/2015] [Indexed: 12/12/2022]
Abstract
Transcriptional regulation requires the binding of transcription factors (TFs) to short sequence-specific DNA motifs, usually located at the gene regulatory regions. Interestingly, based on a vast amount of data accumulated from genomic assays, it has been shown that only a small fraction of all potential binding sites containing the consensus motif of a given TF actually bind the protein. Recent in vitro binding assays, which exclude the effects of the cellular environment, also demonstrate selective TF binding. An intriguing conjecture is that the surroundings of cognate binding sites have unique characteristics that distinguish them from other sequences containing a similar motif that are not bound by the TF. To test this hypothesis, we conducted a comprehensive analysis of the sequence and DNA shape features surrounding the core-binding sites of 239 and 56 TFs extracted from in vitro HT-SELEX binding assays and in vivo ChIP-seq data, respectively. Comparing the nucleotide content of the regions around the TF-bound sites to the counterpart unbound regions containing the same consensus motifs revealed significant differences that extend far beyond the core-binding site. Specifically, the environment of the bound motifs demonstrated unique sequence compositions, DNA shape features, and overall high similarity to the core-binding motif. Notably, the regions around the binding sites of TFs that belong to the same TF families exhibited similar features, with high agreement between the in vitro and in vivo data sets. We propose that these unique features assist in guiding TFs to their cognate binding sites.
Collapse
Affiliation(s)
- Iris Dror
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel; Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics, and Computer Science, University of Southern California, Los Angeles, California 90089, USA
| | - Tamar Golan
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Carmit Levy
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Remo Rohs
- Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics, and Computer Science, University of Southern California, Los Angeles, California 90089, USA
| | - Yael Mandel-Gutfreund
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| |
Collapse
|
47
|
Deng Z, Wang Q, Liu Z, Zhang M, Machado ACD, Chiu TP, Feng C, Zhang Q, Yu L, Qi L, Zheng J, Wang X, Huo X, Qi X, Li X, Wu W, Rohs R, Li Y, Chen Z. Mechanistic insights into metal ion activation and operator recognition by the ferric uptake regulator. Nat Commun 2015; 6:7642. [PMID: 26134419 PMCID: PMC4506495 DOI: 10.1038/ncomms8642] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 05/27/2015] [Indexed: 01/21/2023] Open
Abstract
Ferric uptake regulator (Fur) plays a key role in the iron homeostasis of prokaryotes, such as bacterial pathogens, but the molecular mechanisms and structural basis of Fur-DNA binding remain incompletely understood. Here, we report high-resolution structures of Magnetospirillum gryphiswaldense MSR-1 Fur in four different states: apo-Fur, holo-Fur, the Fur-feoAB1 operator complex and the Fur-Pseudomonas aeruginosa Fur box complex. Apo-Fur is a transition metal ion-independent dimer whose binding induces profound conformational changes and confers DNA-binding ability. Structural characterization, mutagenesis, biochemistry and in vivo data reveal that Fur recognizes DNA by using a combination of base readout through direct contacts in the major groove and shape readout through recognition of the minor-groove electrostatic potential by lysine. The resulting conformational plasticity enables Fur binding to diverse substrates. Our results provide insights into metal ion activation and substrate recognition by Fur that suggest pathways to engineer magnetotactic bacteria and antipathogenic drugs.
Collapse
Affiliation(s)
- Zengqin Deng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Qing Wang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Zhao Liu
- Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Manfeng Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Ana Carolina Dantas Machado
- Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics, and Computer Science, University of Southern California, Los Angeles, California 90089, USA
| | - Tsu-Pei Chiu
- Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics, and Computer Science, University of Southern California, Los Angeles, California 90089, USA
| | - Chong Feng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Qi Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Lin Yu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Lei Qi
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Jiangge Zheng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Xu Wang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - XinMei Huo
- Institute of Apicultural Research, Key Laboratory of Pollinating Insect Biology, Chinese Academy of Agricultural Science, Beijing 100093, China
| | - Xiaoxuan Qi
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Xiaorong Li
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Remo Rohs
- Molecular and Computational Biology Program, Departments of Biological Sciences, Chemistry, Physics, and Computer Science, University of Southern California, Los Angeles, California 90089, USA
| | - Ying Li
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| |
Collapse
|
48
|
Temporal hierarchy of gene expression mediated by transcription factor binding affinity and activation dynamics. mBio 2015; 6:e00686-15. [PMID: 26015501 PMCID: PMC4447250 DOI: 10.1128/mbio.00686-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Understanding cellular responses to environmental stimuli requires not only the knowledge of specific regulatory components but also the quantitative characterization of the magnitude and timing of regulatory events. The two-component system is one of the major prokaryotic signaling schemes and is the focus of extensive interest in quantitative modeling and investigation of signaling dynamics. Here we report how the binding affinity of the PhoB two-component response regulator (RR) to target promoters impacts the level and timing of expression of PhoB-regulated genes. Information content has often been used to assess the degree of conservation for transcription factor (TF)-binding sites. We show that increasing the information content of PhoB-binding sites in designed phoA promoters increased the binding affinity and that the binding affinity and concentration of phosphorylated PhoB (PhoB~P) together dictate the level and timing of expression of phoA promoter variants. For various PhoB-regulated promoters with distinct promoter architectures, expression levels appear not to be correlated with TF-binding affinities, in contrast to the intuitive and oversimplified assumption that promoters with higher affinity for a TF tend to have higher expression levels. However, the expression timing of the core set of PhoB-regulated genes correlates well with the binding affinity of PhoB~P to individual promoters and the temporal hierarchy of gene expression appears to be related to the function of gene products during the phosphate starvation response. Modulation of the information content and binding affinity of TF-binding sites may be a common strategy for temporal programming of the expression profile of RR-regulated genes. IMPORTANCE A single TF often orchestrates the expression of multiple genes in response to environmental stimuli. It is not clear how different TF-binding sites within the regulon dictate the expression profile. Our studies of Escherichia coli PhoB, a response regulator that controls expression of a core set of phosphate assimilation genes in response to phosphate starvation, showed that expression levels of PhoB-regulated genes are under sophisticated control and do not follow a simple correlation with the binding affinity of PhoB~P to individual promoters. However, the expression timing correlates with the PhoB-binding affinity and gene functions. Genes involved in direct Pi uptake contain high-affinity sites and are transcribed earlier than genes involved in phosphorus scavenging. This illustrates an elaborate mechanism of temporally programmed gene expression, even for nondevelopmental pathways.
Collapse
|
49
|
Comoglio F, Schlumpf T, Schmid V, Rohs R, Beisel C, Paro R. High-resolution profiling of Drosophila replication start sites reveals a DNA shape and chromatin signature of metazoan origins. Cell Rep 2015; 11:821-34. [PMID: 25921534 DOI: 10.1016/j.celrep.2015.03.070] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/09/2015] [Accepted: 03/29/2015] [Indexed: 11/16/2022] Open
Abstract
At every cell cycle, faithful inheritance of metazoan genomes requires the concerted activation of thousands of DNA replication origins. However, the genetic and chromatin features defining metazoan replication start sites remain largely unknown. Here, we delineate the origin repertoire of the Drosophila genome at high resolution. We address the role of origin-proximal G-quadruplexes and suggest that they transiently stall replication forks in vivo. We dissect the chromatin configuration of replication origins and identify a rich spatial organization of chromatin features at initiation sites. DNA shape and chromatin configurations, not strict sequence motifs, mark and predict origins in higher eukaryotes. We further examine the link between transcription and origin firing and reveal that modulation of origin activity across cell types is intimately linked to cell-type-specific transcriptional programs. Our study unravels conserved origin features and provides unique insights into the relationship among DNA topology, chromatin, transcription, and replication initiation across metazoa.
Collapse
Affiliation(s)
- Federico Comoglio
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Tommy Schlumpf
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Virginia Schmid
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Remo Rohs
- Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Christian Beisel
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Renato Paro
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland; Faculty of Science, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland.
| |
Collapse
|
50
|
Trubitsyna M, Grey H, Houston DR, Finnegan DJ, Richardson JM. Structural Basis for the Inverted Repeat Preferences of mariner Transposases. J Biol Chem 2015; 290:13531-40. [PMID: 25869132 PMCID: PMC4505599 DOI: 10.1074/jbc.m115.636704] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Indexed: 11/10/2022] Open
Abstract
The inverted repeat (IR) sequences delimiting the left and right ends of many naturally active mariner DNA transposons are non-identical and have different affinities for their transposase. We have compared the preferences of two active mariner transposases, Mos1 and Mboumar-9, for their imperfect transposon IRs in each step of transposition: DNA binding, DNA cleavage, and DNA strand transfer. A 3.1 Å resolution crystal structure of the Mos1 paired-end complex containing the pre-cleaved left IR sequences reveals the molecular basis for the reduced affinity of the Mos1 transposase DNA-binding domain for the left IR as compared with the right IR. For both Mos1 and Mboumar-9, in vitro DNA transposition is most efficient when the preferred IR sequence is present at both transposon ends. We find that this is due to the higher efficiency of cleavage and strand transfer of the preferred transposon end. We show that the efficiency of Mboumar-9 transposition is improved almost 4-fold by changing the 3′ base of the preferred Mboumar-9 IR from guanine to adenine. This preference for adenine at the reactive 3′ end for both Mos1 and Mboumar-9 may be a general feature of mariner transposition.
Collapse
Affiliation(s)
| | - Heather Grey
- Institute of Structural and Molecular Biology, School of Biological Sciences, University of Edinburgh, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom
| | - Douglas R Houston
- Institute of Structural and Molecular Biology, School of Biological Sciences, University of Edinburgh, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom
| | | | - Julia M Richardson
- Institute of Structural and Molecular Biology, School of Biological Sciences, University of Edinburgh, The King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom
| |
Collapse
|