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Talyzina A, Han Y, Banerjee C, Fishbain S, Reyes A, Vafabakhsh R, He Y. Structural basis of TFIIIC-dependent RNA polymerase III transcription initiation. Mol Cell 2023; 83:2641-2652.e7. [PMID: 37402369 PMCID: PMC10528418 DOI: 10.1016/j.molcel.2023.06.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/02/2023] [Accepted: 06/08/2023] [Indexed: 07/06/2023]
Abstract
RNA polymerase III (Pol III) is responsible for transcribing 5S ribosomal RNA (5S rRNA), tRNAs, and other short non-coding RNAs. Its recruitment to the 5S rRNA promoter requires transcription factors TFIIIA, TFIIIC, and TFIIIB. Here, we use cryoelectron microscopy (cryo-EM) to visualize the S. cerevisiae complex of TFIIIA and TFIIIC bound to the promoter. Gene-specific factor TFIIIA interacts with DNA and acts as an adaptor for TFIIIC-promoter interactions. We also visualize DNA binding of TFIIIB subunits, Brf1 and TBP (TATA-box binding protein), which results in the full-length 5S rRNA gene wrapping around the complex. Our smFRET study reveals that the DNA within the complex undergoes both sharp bending and partial dissociation on a slow timescale, consistent with the model predicted from our cryo-EM results. Our findings provide new insights into the transcription initiation complex assembly on the 5S rRNA promoter and allow us to directly compare Pol III and Pol II transcription adaptations.
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Affiliation(s)
- Anna Talyzina
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Yan Han
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Chiranjib Banerjee
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Susan Fishbain
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Alexis Reyes
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Reza Vafabakhsh
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA; Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, IL, USA.
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2
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Talyzina A, Han Y, Banerjee C, Fishbain S, Reyes A, Vafabakhsh R, He Y. Structural basis of TFIIIC-dependent RNA Polymerase III transcription initiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.16.540967. [PMID: 37292922 PMCID: PMC10245719 DOI: 10.1101/2023.05.16.540967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
RNA Polymerase III (Pol III) is responsible for transcribing 5S ribosomal RNA (5S rRNA), tRNAs, and other short non-coding RNAs. Its recruitment to the 5S rRNA promoter requires transcription factors TFIIIA, TFIIIC, and TFIIIB. Here we use cryo-electron microscopy to visualize the S. cerevisiae complex of TFIIIA and TFIIIC bound to the promoter. Brf1-TBP binding further stabilizes the DNA, resulting in the full-length 5S rRNA gene wrapping around the complex. Our smFRET study reveals that the DNA undergoes both sharp bending and partial dissociation on a slow timescale, consistent with the model predicted from our cryo-EM results. Our findings provide new insights into the mechanism of how the transcription initiation complex assembles on the 5S rRNA promoter, a crucial step in Pol III transcription regulation.
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Affiliation(s)
- Anna Talyzina
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States
| | - Yan Han
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
| | - Chiranjib Banerjee
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
| | - Susan Fishbain
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
| | - Alexis Reyes
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States
| | - Reza Vafabakhsh
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, United States
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, IL, United States
- Lead contact
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3
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Yu B, Wang X, Wang T, Iwahara J. DNA base order parameter determination without influence of chemical exchange. Methods 2023; 210:1-9. [PMID: 36596431 PMCID: PMC9898221 DOI: 10.1016/j.ymeth.2022.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/23/2022] [Accepted: 12/30/2022] [Indexed: 01/01/2023] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a versatile tool used to investigate the dynamic properties of biological macromolecules and their complexes. NMR relaxation data can provide order parameters S2, which represent the mobility of bond vectors reorienting within a molecular frame. Determination of S2 parameters typically involves the use of transverse NMR relaxation rates. However, the accuracy in S2 determination can be diminished by elevation of the transverse relaxation rates through conformational or chemical exchange involving protonation/deprotonation or non-Watson-Crick base-pair states of nucleic acids. Here, we propose an approach for determination of S2 parameters without the influence of exchange processes. This approach utilizes transverse and longitudinal 13C chemical shift anisotropy (CSA) - dipole-dipole (DD) cross-correlation rates instead of 13C transverse relaxation rates. Anisotropy in rotational diffusion is taken into consideration. An application of this approach to nucleotide base CH groups of a uniformly 13C/15N-labeled DNA duplex is demonstrated.
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Affiliation(s)
- Binhan Yu
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xi Wang
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tianzhi Wang
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Junji Iwahara
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.
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4
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Neuhaus D. Zinc finger structure determination by NMR: Why zinc fingers can be a handful. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 130-131:62-105. [PMID: 36113918 PMCID: PMC7614390 DOI: 10.1016/j.pnmrs.2022.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/09/2022] [Accepted: 07/10/2022] [Indexed: 06/07/2023]
Abstract
Zinc fingers can be loosely defined as protein domains containing one or more tetrahedrally-co-ordinated zinc ions whose role is to stabilise the structure rather than to be involved in enzymatic chemistry; such zinc ions are often referred to as "structural zincs". Although structural zincs can occur in proteins of any size, they assume particular significance for very small protein domains, where they are often essential for maintaining a folded state. Such small structures, that sometimes have only marginal stability, can present particular difficulties in terms of sample preparation, handling and structure determination, and early on they gained a reputation for being resistant to crystallisation. As a result, NMR has played a more prominent role in structural studies of zinc finger proteins than it has for many other types of proteins. This review will present an overview of the particular issues that arise for structure determination of zinc fingers by NMR, and ways in which these may be addressed.
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Affiliation(s)
- David Neuhaus
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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5
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Wang Q, Daiß JL, Xu Y, Engel C. Snapshots of RNA polymerase III in action - A mini review. Gene 2022; 821:146282. [PMID: 35149153 DOI: 10.1016/j.gene.2022.146282] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/20/2022] [Accepted: 02/03/2022] [Indexed: 11/04/2022]
Abstract
RNA polymerase (Pol) III is responsible for the transcription of tRNAs, 5S rRNA, U6 snRNA, and other non-coding RNAs. Transcription factors such as TFIIIA, -B, -C, SNAPc, and Maf1 are required for promoter recognition, promoter opening, and Pol III activity regulation. Recent developments in cryo-electron microscopy and advanced purification approaches for endogenous multi-subunit complexes accelerated structural studies resulting in detailed structural insights which allowed an in-depth understanding of the molecular mechanisms underlying Pol III transcription. Here, we summarize structural data on Pol III and its regulating factors providing a three-dimensional framework to guide further analysis of RNA polymerase III.
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Affiliation(s)
- Qianmin Wang
- State Key Laboratory of Oncogenes and Related Genes, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Institute of Precision Medicine, Shanghai, China; Present address: Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Julia L Daiß
- Regensburg Center for Biochemistry, University of Regensburg, 93053, Regensburg, Germany
| | - Youwei Xu
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
| | - Christoph Engel
- Regensburg Center for Biochemistry, University of Regensburg, 93053, Regensburg, Germany.
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Cognate DNA Recognition by Engrailed Homeodomain Involves a Conformational Change Controlled via an Electrostatic-Spring-Loaded Latch. Int J Mol Sci 2022; 23:ijms23052412. [PMID: 35269555 PMCID: PMC8910618 DOI: 10.3390/ijms23052412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 02/01/2023] Open
Abstract
Transcription factors must scan genomic DNA, recognize the cognate sequence of their control element(s), and bind tightly to them. The DNA recognition process is primarily carried out by their DNA binding domains (DBD), which interact with the cognate site with high affinity and more weakly with any other DNA sequence. DBDs are generally thought to bind to their cognate DNA without changing conformation (lock-and-key). Here, we used nuclear magnetic resonance and circular dichroism to investigate the interplay between DNA recognition and DBD conformation in the engrailed homeodomain (enHD), as a model case for the homeodomain family of eukaryotic DBDs. We found that the conformational ensemble of enHD is rather flexible and becomes gradually more disordered as ionic strength decreases following a Debye–Hückel’s dependence. Our analysis indicates that enHD’s response to ionic strength is mediated by a built-in electrostatic spring-loaded latch that operates as a conformational transducer. We also found that, at moderate ionic strengths, enHD changes conformation upon binding to cognate DNA. This change is of larger amplitude and somewhat orthogonal to the response to ionic strength. As a consequence, very high ionic strengths (e.g., 700 mM) block the electrostatic-spring-loaded latch and binding to cognate DNA becomes lock-and-key. However, the interplay between enHD conformation and cognate DNA binding is robust across a range of ionic strengths (i.e., 45 to 300 mM) that covers the physiologically-relevant conditions. Therefore, our results demonstrate the presence of a mechanism for the conformational control of cognate DNA recognition on a eukaryotic DBD. This mechanism can function as a signal transducer that locks the DBD in place upon encountering the cognate site during active DNA scanning. The electrostatic-spring-loaded latch of enHD can also enable the fine control of DNA recognition in response to transient changes in local ionic strength induced by variate physiological processes.
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Boisvert O, Létourneau D, Delattre P, Tremblay C, Jolibois É, Montagne M, Lavigne P. Zinc Fingers 10 and 11 of Miz-1 undergo conformational exchange to achieve specific DNA binding. Structure 2021; 30:623-636.e5. [PMID: 34963061 DOI: 10.1016/j.str.2021.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/08/2021] [Accepted: 12/01/2021] [Indexed: 11/18/2022]
Abstract
Miz-1 (ZBTB17) is a poly-zinc finger BTB/POZ transcription factor with 12 consecutive C2H2 zinc fingers (ZFs) that binds transcriptional start sites (TSSs) to regulate the expression of genes involved in cell development and proliferation. As of now, it is not known which of the 12 consecutive ZFs are responsible for the recognition of the 24 base pair consensus sequence found at these TSSs. Evidence suggests ZFs 7-12 plays this role. We provide validation for this and describe the structural and dynamical characterization of unprecedented conformational exchange in the linker between ZFs 10 and 11. This conformational exchange uncouples ZFs 7-10 from 11 and 12 and promotes a scanning-recognition mechanism through which the two segments cooperate to bind two sub-sites at both ends of the consensus. We further show that this can result in the coiling of TSSs as part of Miz-1's mechanism of transcriptional transactivation.
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Affiliation(s)
- Olivier Boisvert
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada
| | - Danny Létourneau
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada
| | - Patrick Delattre
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada
| | - Cynthia Tremblay
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada
| | - Émilie Jolibois
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada
| | - Martin Montagne
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada
| | - Pierre Lavigne
- Département de biochimie et de génomique fonctionnelle, Institut de Pharmacologie de Sherbrooke and PROTÉO, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001 12 Avenue N, Sherbrooke, Quebec J1H 5N4, Canada.
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8
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The role of zinc finger linkers in zinc finger protein binding to DNA. J Comput Aided Mol Des 2021; 35:973-986. [PMID: 34350488 DOI: 10.1007/s10822-021-00413-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
Zinc finger proteins (ZFP) play important roles in cellular processes. The DNA binding region of ZFP consists of 3 zinc finger DNA binding domains connected by amino acid linkers, the sequence TGQKP connects ZF1 and ZF2, and TGEKP connects ZF2 with ZF3. Linkers act to tune the zinc finger protein in the right position to bind its DNA target, the type of amino acid residues and length of linkers reflect on ZF1-ZF2-ZF3 interactions and contribute to the search and recognition process of ZF protein to its DNA target. Linker mutations and the affinity of the resulting mutants to specific and nonspecific DNA targets were studied by MD simulations and MM_GB(PB)SA. The affinity of mutants to DNA varied with type and position of amino acid residue. Mutation of K in TGQKP resulted in loss in affinity due to the loss of positive K interaction with phosphates, mutation of G showed loss in affinity to DNA, WT protein and all linker mutants showed loss in affinity to a nonspecific DNA target, this finding confirms previous reports which interpreted this loss in affinity as due to ZF1 having an anchoring role, and ZF3 playing an explorer role in the binding mechanism. The change in ZFP-DNA affinity with linker mutations is discussed in view of protein structure and role of linker residues in binding.
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9
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Nishikawa T, Wojciak JM, Dyson HJ, Wright PE. RNA Binding by the KTS Splice Variants of Wilms' Tumor Suppressor Protein WT1. Biochemistry 2020; 59:3889-3901. [PMID: 32955251 DOI: 10.1021/acs.biochem.0c00602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Wilms' tumor suppressor protein WT1 regulates the expression of multiple genes through binding of the Cys2-His2 zinc finger domain to promoter sites. WT1 has also been proposed to be involved in post-transcriptional regulation, by binding to RNA using the same set of zinc fingers. WT1 has two major splice variants, where the Lys-Thr-Ser (KTS) tripeptide is inserted into the linker between the third and fourth zinc fingers. To obtain insights into the mechanism by which the different WT1 splice variants recognize both DNA and RNA, we have determined the solution structure of the WT1 (-KTS) zinc finger domain in complex with a 29mer stem-loop RNA. Zinc fingers 1-3 bind in a widened major groove favored by the presence of a bulge nucleotide in the double-stranded helical stem. Fingers 2 and 3 make specific contacts with the nucleobases in a conserved AUGG sequence in the helical stem. Nuclear magnetic resonance chemical shift mapping and relaxation analysis show that fingers 1-3 of the two splice variants (-KTS and +KTS) of WT1 form similar complexes with RNA. Finger 4 of the -KTS isoform interacts weakly with the RNA loop, an interaction that is abrogated in the +KTS isoform, and both isoforms bind with similar affinity to the RNA. In contrast, finger 4 is required for high-affinity binding to DNA and insertion of KTS into the linker of fingers 3 and 4 abrogates DNA binding. While finger 1 is required for RNA binding, it is dispensable for binding to consensus DNA sites.
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Affiliation(s)
- Tadateru Nishikawa
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jonathan M Wojciak
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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10
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Yoon C, Lee D, Lee SJ. Regulation of the Central Dogma through Bioinorganic Events with Metal Coordination for Specific Interactions. B KOREAN CHEM SOC 2020. [DOI: 10.1002/bkcs.12090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Chungwoon Yoon
- Department of Chemistry Institute for Molecular Biology and Genetics, Jeonbuk National University Jeonju 54896 Republic of Korea
| | - Dong‐Heon Lee
- Department of Chemistry Institute for Molecular Biology and Genetics, Jeonbuk National University Jeonju 54896 Republic of Korea
| | - Seung Jae Lee
- Department of Chemistry Institute for Molecular Biology and Genetics, Jeonbuk National University Jeonju 54896 Republic of Korea
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11
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Padjasek M, Kocyła A, Kluska K, Kerber O, Tran JB, Krężel A. Structural zinc binding sites shaped for greater works: Structure-function relations in classical zinc finger, hook and clasp domains. J Inorg Biochem 2020; 204:110955. [DOI: 10.1016/j.jinorgbio.2019.110955] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/08/2019] [Accepted: 12/01/2019] [Indexed: 12/12/2022]
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12
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Kluska K, Adamczyk J, Krężel A. Metal binding properties, stability and reactivity of zinc fingers. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.04.009] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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13
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Mazmanian K, Dudev T, Lim C. How First Shell–Second Shell Interactions and Metal Substitution Modulate Protein Function. Inorg Chem 2018; 57:14052-14061. [DOI: 10.1021/acs.inorgchem.8b01029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Karine Mazmanian
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 10617, Taiwan
- Taiwan and Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Todor Dudev
- Faculty of Chemistry and Pharmacy, Sofia University, Sofia 1164, Bulgaria
| | - Carmay Lim
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
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14
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Baird-Titus JM, Thapa M, Doerdelmann T, Combs KA, Rance M. Lysine Side-Chain Dynamics in the Binding Site of Homeodomain/DNA Complexes As Observed by NMR Relaxation Experiments and Molecular Dynamics Simulations. Biochemistry 2018; 57:2796-2813. [PMID: 29664630 DOI: 10.1021/acs.biochem.8b00195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An important but poorly characterized contribution to the thermodynamics of protein-DNA interactions is the loss of entropy that occurs from restricting the conformational freedom of amino acid side chains. The effect of restricting the flexibility of several side chains at a protein-DNA interface may be comparable in many cases to the other factors that determine the binding thermodynamics and may, therefore, play a key role in dictating the binding affinity and/or specificity. Because the entropic contributions, including the presence and influence of side-chain dynamics, are especially difficult to estimate based on structural information, it is important to pursue experimental and theoretical studies that can provide direct information regarding these issues. We report on studies of a model system, the homeodomain/DNA complex, focusing on the Lys50 class of homeodomains where a key lysine residue in position 50 was shown previously to be critical for binding site specificity. NMR methodology was employed for determining the dynamics of lysine side-chain amino groups via 15N relaxation measurements in the Lys50-class homeodomains from the Drosophila protein Bicoid and the human protein Pitx2. In the case of Pitx2, complexes with both a consensus and a nonconsensus DNA binding site were examined. NMR-derived order parameters indicated moderate to substantial conformational freedom for the lysine NH3+ group in the complexes studied. To complement the experimental NMR measurements, molecular dynamics simulations were performed for the consensus complexes to gain further, detailed insights regarding the dynamics of the Lys50 side chain and other important residues in the protein-DNA interface.
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Affiliation(s)
- Jamie M Baird-Titus
- Department of Chemistry and Physical Sciences , Mount St. Joseph University , Cincinnati , Ohio 45233 , United States
| | - Mahendra Thapa
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45220 , United States
| | - Thomas Doerdelmann
- Department of Molecular Genetics, Biochemistry and Microbiology , University of Cincinnati College of Medicine , Cincinnati , Ohio 45267 , United States
| | - Kelly A Combs
- Department of Molecular Genetics, Biochemistry and Microbiology , University of Cincinnati College of Medicine , Cincinnati , Ohio 45267 , United States
| | - Mark Rance
- Department of Molecular Genetics, Biochemistry and Microbiology , University of Cincinnati College of Medicine , Cincinnati , Ohio 45267 , United States
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15
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Ryu JH, Jung HJ, Konishi S, Kim HH, Park ZY, Kim JI. Structure-activity relationships of ω-Agatoxin IVA in lipid membranes. Biochem Biophys Res Commun 2017; 482:170-175. [DOI: 10.1016/j.bbrc.2016.11.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 11/06/2016] [Indexed: 11/29/2022]
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16
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Raposo AN, Gomes AJP. Computational 3D Assembling Methods for DNA: A Survey. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2016; 13:1068-1085. [PMID: 26701896 DOI: 10.1109/tcbb.2015.2510008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
DNA encodes the genetic information of most living beings, except viruses that use RNA. Unlike other types of molecules, DNA is not usually described by its atomic structure being instead usually described by its base-pair sequence, i.e., the textual sequence of its subsidiary molecules known as nucleotides ( adenine (A), cytosine (C), guanine (G), and thymine (T)). The three-dimensional assembling of DNA molecules based on its base-pair sequence has been, for decades, a topic of interest for many research groups all over the world. In this paper, we survey the major methods found in the literature to assemble and visualize DNA molecules from their base-pair sequences. We divided these methods into three categories: predictive methods, adaptive methods, and thermodynamic methods . Predictive methods aim to predict a conformation of the DNA from its base pair sequence, while the goal of adaptive methods is to assemble DNA base-pairs sequences along previously known conformations, as needed in scenarios such as DNA Monte Carlo simulations. Unlike these two geometric methods, thermodynamic methods are energy-based and aim to predict secondary structural motifs of DNA in cases where hydrogen bonds between base pairs might be broken because of temperature changes. We also present the major software tools that implements predictive, adaptive, and thermodynamic methods.
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17
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Clark MD, Zhang Y, Radhakrishnan I. Solution NMR Studies of an Alternative Mode of Sin3 Engagement by the Sds3 Subunit in the Histone Deacetylase-Associated Sin3L/Rpd3L Corepressor Complex. J Mol Biol 2015; 427:3817-23. [PMID: 26522936 DOI: 10.1016/j.jmb.2015.10.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/05/2015] [Accepted: 10/22/2015] [Indexed: 11/19/2022]
Abstract
The Sds3 transcriptional corepressor facilitates the assembly of the 1- to 2-MDa histone deacetylase-associated Sin3L/Rpd3L complex by providing a crucial homodimerization activity. Sds3 engages the scaffolding protein Sin3A, via a bipartite motif within the Sin3 interaction domain (SID) comprising a helix and an extended segment. Here, we show that the SID samples two discrete, substantially populated conformations with lifetimes in the tens of milliseconds range. The two conformations differ via a translation of the main chain and the corresponding side chains in the 5- to 7-Å range. Given the close proximity of the SID to other functional motifs in Sds3 at the sequence level, the conformational exchange has the potential to regulate these activities.
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Affiliation(s)
- Michael David Clark
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Yongbo Zhang
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Ishwar Radhakrishnan
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
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Romero JM, Martin M, Ramirez CL, Dumas VG, Marti MA. Efficient Calculation of Enzyme Reaction Free Energy Profiles Using a Hybrid Differential Relaxation Algorithm: Application to Mycobacterial Zinc Hydrolases. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 100:33-65. [PMID: 26415840 DOI: 10.1016/bs.apcsb.2015.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Determination of the free energy profile for an enzyme reaction mechanism is of primordial relevance, paving the way for our understanding of the enzyme's catalytic power at the molecular level. Although hybrid, mostly DFT-based, QM/MM methods have been extensively applied to this type of studies, achieving accurate and statistically converged results at a moderate computational cost is still an open challenge. Recently, we have shown that accurate results can be achieved in less computational time, combining Jarzynski's relationship with a hybrid differential relaxation algorithm (HyDRA), which allows partial relaxation of the solvent during the nonequilibrium steering of the reaction. In this work, we have applied this strategy to study two mycobacterial zinc hydrolases. Mycobacterium tuberculosis infections are still a worldwide problem and thus characterization and validation of new drug targets is an intense field of research. Among possible drug targets, recently two essential zinc hydrolases, MshB (Rv1170) and MA-amidase (Rv3717), have been proposed and structurally characterized. Although possible mechanisms have been proposed by analogy to the widely studied human Zn hydrolases, several key issues, particularly those related to Zn coordination sphere and its role in catalysis, remained unanswered. Our results show that mycobacterial Zn hydrolases share a basic two-step mechanism. First, the attacking water becomes deprotonated by the conserved base and establishes the new C-O bond leading to a tetrahedral intermediate. The intermediate requires moderate reorganization to allow for proton transfer to the amide N and C-N bond breaking to occur in the second step. Zn ion plays a key role in stabilizing the tetrahedral intermediate and balancing the negative charge of the substrate during hydroxide ion attack. Finally, comparative analysis of other Zn hydrolases points to a convergent mechanistic evolution.
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Affiliation(s)
- Juan Manuel Romero
- Instituto de Química Física de los Materiales Medio Ambiente y Energía (INQUIMAE), UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Mariano Martin
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Claudia Lilián Ramirez
- Instituto de Química Física de los Materiales Medio Ambiente y Energía (INQUIMAE), UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Victoria Gisel Dumas
- Instituto de Química Física de los Materiales Medio Ambiente y Energía (INQUIMAE), UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina; Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marcelo Adrián Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina; Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Buenos Aires, Argentina.
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19
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Richard GF. Shortening trinucleotide repeats using highly specific endonucleases: a possible approach to gene therapy? Trends Genet 2015; 31:177-86. [PMID: 25743488 DOI: 10.1016/j.tig.2015.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 12/31/2022]
Abstract
Trinucleotide repeat expansions are involved in more than two dozen neurological and developmental disorders. Conventional therapeutic approaches aimed at regulating the expression level of affected genes, which rely on drugs, oligonucleotides, and/or transgenes, have met with only limited success so far. An alternative approach is to shorten repeats to non-pathological lengths using highly specific nucleases. Here, I review early experiments using meganucleases, zinc-finger nucleases (ZFN), and transcription-activator like effector nucleases (TALENs) to contract trinucleotide repeats, and discuss the possibility of using CRISPR-Cas nucleases to the same end. Although this is a nascent field, I explore the possibility of designing nucleases and effectively delivering them in the context of gene therapy.
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Affiliation(s)
- Guy-Franck Richard
- Institut Pasteur, Department Genomes and Genetics, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 3525, 25 Rue du Dr Roux, 75015 Paris, France
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20
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Esadze A, Zandarashvili L, Iwahara J. Effective strategy to assign ¹H- ¹⁵N heteronuclear correlation NMR signals from lysine side-chain NH3₃⁺ groups of proteins at low temperature. JOURNAL OF BIOMOLECULAR NMR 2014; 60:23-7. [PMID: 25129623 PMCID: PMC4160661 DOI: 10.1007/s10858-014-9854-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/06/2014] [Indexed: 05/15/2023]
Abstract
Recent studies have shown that lysine side-chain NH3(+) groups are excellent probes for NMR investigations of dynamics involving hydrogen bonds and ion pairs relevant to protein function. However, due to rapid hydrogen exchange, observation of (1)H-(15)N NMR cross peaks from lysine NH3(+) groups often requires use of a relatively low temperature, which renders difficulty in resonance assignment. Here we present an effective strategy to assign (1)H and (15)N resonances of NH3(+) groups at low temperatures. This strategy involves two new (1)H/(13)C/(15)N triple-resonance experiments for lysine side chains. Application to a protein-DNA complex is demonstrated.
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21
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Vandevenne M, Jacques DA, Artuz C, Nguyen CD, Kwan AHY, Segal DJ, Matthews JM, Crossley M, Guss JM, Mackay JP. New insights into DNA recognition by zinc fingers revealed by structural analysis of the oncoprotein ZNF217. J Biol Chem 2013; 288:10616-27. [PMID: 23436653 DOI: 10.1074/jbc.m112.441451] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Classical zinc fingers (ZFs) are one of the most abundant and best characterized DNA-binding domains. Typically, tandem arrays of three or more ZFs bind DNA target sequences with high affinity and specificity, and the mode of DNA recognition is sufficiently well understood that tailor-made ZF-based DNA-binding proteins can be engineered. We have shown previously that a two-zinc finger unit found in the transcriptional coregulator ZNF217 recognizes DNA but with an affinity and specificity that is lower than other ZF arrays. To investigate the basis for these differences, we determined the structure of a ZNF217-DNA complex. We show that although the overall position of the ZFs on the DNA closely resembles that observed for other ZFs, the side-chain interaction pattern differs substantially from the canonical model. The structure also reveals the presence of two methyl-π interactions, each featuring a tyrosine contacting a thymine methyl group. To our knowledge, interactions of this type have not previously been described in classical ZF-DNA complexes. Finally, we investigated the sequence specificity of this two-ZF unit and discuss how ZNF217 might discriminate its target DNA sites in the cell.
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Affiliation(s)
- Marylène Vandevenne
- School of Molecular Bioscience, University of Sydney, New South Wales, 2006 Australia
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22
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Structure, dynamics and domain organization of the repeat protein Cin1 from the apple scab fungus. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1118-28. [PMID: 22771296 DOI: 10.1016/j.bbapap.2012.06.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/16/2012] [Accepted: 06/26/2012] [Indexed: 11/20/2022]
Abstract
Venturia inaequalis is a hemi-biotrophic fungus that causes scab disease of apple. A recently-identified gene from this fungus, cin1 (cellophane-induced 1), is up-regulated over 1000-fold in planta and considerably on cellophane membranes, and encodes a cysteine-rich secreted protein of 523 residues with eight imperfect tandem repeats of ~60 amino acids. The Cin1 sequence has no homology to known proteins and appears to be genus-specific; however, Cin1 repeats and other repeat domains may be structurally similar. An NMR-derived structure of the first two repeat domains of Cin1 (Cin1-D1D2) and a low-resolution model of the full-length protein (Cin1-FL) using SAXS data were determined. The structure of Cin1-D1D2 reveals that each domain comprises a core helix-loop-helix (HLH) motif as part of a three-helix bundle, and is stabilized by two intra-domain disulfide bonds. Cin1-D1D2 adopts a unique protein fold as DALI and PDBeFOLD analysis identified no structural homology. A (15)N backbone NMR dynamic analysis of Cin1-D1D2 showed that a short stretch of the inter-domain linker has large amplitude motions that give rise to reciprocal domain-domain mobility. This observation was supported by SAXS data modeling, where the scattering length density envelope remains thick at the domain-domain boundary, indicative of inter-domain dynamics. Cin1-FL SAXS data models a loosely-packed arrangement of domains, rather than the canonical parallel packing of adjacent HLH repeats observed in α-solenoid repeat proteins. Together, these data suggest that the repeat domains of Cin1 display a "beads-on-a-string" organization with inherent inter-domain flexibility that is likely to facilitate interactions with target ligands.
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23
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Asymmetrical roles of zinc fingers in dynamic DNA-scanning process by the inducible transcription factor Egr-1. Proc Natl Acad Sci U S A 2012; 109:E1724-32. [PMID: 22675124 DOI: 10.1073/pnas.1121500109] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Egr-1 is an inducible transcription factor that recognizes 9-bp target DNA sites via three zinc finger domains and activates genes in response to cellular stimuli such as synaptic signals and vascular stresses. Using spectroscopic and computational approaches, we have studied structural, dynamic, and kinetic aspects of the DNA-scanning process in which Egr-1 is nonspecifically bound to DNA and perpetually changes its location on DNA. Our NMR data indicate that Egr-1 undergoes highly dynamic domain motions when scanning DNA. In particular, the zinc finger 1 (ZF1) of Egr-1 in the nonspecific complex is mainly dissociated from DNA and undergoes collective motions on a nanosecond timescale, whereas zinc fingers 2 and 3 (ZF2 and ZF3, respectively) are bound to DNA. This was totally unexpected because the previous crystallographic studies of the specific complex indicated that all of Egr-1's three zinc fingers are equally involved in binding to a target DNA site. Mutations that are expected to enhance ZF1's interactions with DNA and with ZF2 were found to reduce ZF1's domain motions in the nonspecific complex suggesting that these interactions dictate the dynamic behavior of ZF1. By experiment and computation, we have also investigated kinetics of Egr-1's translocation between two nonspecific DNA duplexes. Our data on the wild type and mutant proteins suggest that the domain dynamics facilitate Egr-1's intersegment transfer that involves transient bridging of two DNA sites. These results shed light on asymmetrical roles of the zinc finger domains for Egr-1 to scan DNA efficiently in the nucleus.
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24
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Clore GM. Exploring translocation of proteins on DNA by NMR. JOURNAL OF BIOMOLECULAR NMR 2011; 51:209-19. [PMID: 21847629 PMCID: PMC3207612 DOI: 10.1007/s10858-011-9555-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 08/03/2011] [Indexed: 05/31/2023]
Abstract
While an extensive body of knowledge has accumulated on the structures of transcription factors, DNA and their complexes from both NMR and crystallography, much less is known at a molecular level regarding the mechanisms whereby transcription factors locate their specific DNA target site within an overwhelming sea of non-specific DNA sites. Indirect kinetic data suggested that three processes are involved in the search procedure: jumping by dissociation of the protein from the DNA followed by re-association at another site, direct transfer from one DNA molecule or segment to another, and one-dimensional sliding. In this brief perspective I summarize recent NMR developments from our laboratory that have permitted direct characterization of the species and molecular mechanisms involved in the target search process, including the detection of highly transient sparsely-populated states. The main tool in these studies involves the application of paramagnetic relaxation enhancement, supplemented by z-exchange spectroscopy, lineshape analysis and residual dipolar couplings. These studies led to the first direct demonstration of rotation-coupled sliding of a protein along the DNA and the direct transfer of a protein from one DNA molecule to another without dissociating into free solution.
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Affiliation(s)
- G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 02892-0520, USA.
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25
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Nunez N, Clifton MMK, Funnell APW, Artuz C, Hallal S, Quinlan KGR, Font J, Vandevenne M, Setiyaputra S, Pearson RCM, Mackay JP, Crossley M. The multi-zinc finger protein ZNF217 contacts DNA through a two-finger domain. J Biol Chem 2011; 286:38190-38201. [PMID: 21908891 DOI: 10.1074/jbc.m111.301234] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Classical C2H2 zinc finger proteins are among the most abundant transcription factors found in eukaryotes, and the mechanisms through which they recognize their target genes have been extensively investigated. In general, a tandem array of three fingers separated by characteristic TGERP links is required for sequence-specific DNA recognition. Nevertheless, a significant number of zinc finger proteins do not contain a hallmark three-finger array of this type, raising the question of whether and how they contact DNA. We have examined the multi-finger protein ZNF217, which contains eight classical zinc fingers. ZNF217 is implicated as an oncogene and in repressing the E-cadherin gene. We show that two of its zinc fingers, 6 and 7, can mediate contacts with DNA. We examine its putative recognition site in the E-cadherin promoter and demonstrate that this is a suboptimal site. NMR analysis and mutagenesis is used to define the DNA binding surface of ZNF217, and we examine the specificity of the DNA binding activity using fluorescence anisotropy titrations. Finally, sequence analysis reveals that a variety of multi-finger proteins also contain two-finger units, and our data support the idea that these may constitute a distinct subclass of DNA recognition motif.
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Affiliation(s)
- Noelia Nunez
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Molly M K Clifton
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Alister P W Funnell
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia; School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales 2052, Australia
| | - Crisbel Artuz
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales 2052, Australia
| | - Samantha Hallal
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Kate G R Quinlan
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Josep Font
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Marylène Vandevenne
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Surya Setiyaputra
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Richard C M Pearson
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia; School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales 2052, Australia
| | - Joel P Mackay
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia
| | - Merlin Crossley
- School of Molecular Bioscience, University of Sydney, New South Wales 2006, Australia; School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales 2052, Australia.
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26
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Dyson HJ. Roles of intrinsic disorder in protein-nucleic acid interactions. MOLECULAR BIOSYSTEMS 2011; 8:97-104. [PMID: 21874205 DOI: 10.1039/c1mb05258f] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Interactions between proteins and nucleic acids typify the role of disordered segments, linkers, tails and other entities in the function of complexes that must form with high affinity and specificity but which must be capable of dissociating when no longer needed. While much of the emphasis in the literature has been on the interactions of disordered proteins with other proteins, disorder is also frequently observed in nucleic acids (particularly RNA) and in the proteins that interact with them. The interactions of disordered proteins with DNA most often manifest as molding of the protein onto the B-form DNA structure, although some well-known instances involve remodeling of the DNA structure that seems to require that the interacting proteins be disordered to various extents in the free state. By contrast, induced fit in RNA-protein interactions has been recognized for many years-the existence and prevalence of this phenomenon provides the clearest possible evidence that RNA and its interactions with proteins must be considered as highly dynamic, and the dynamic nature of RNA and its multiplicity of folded and unfolded states is an integral part of its nature and function.
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Affiliation(s)
- H Jane Dyson
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, USA.
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27
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Payne MA. Zinc finger structure-function in Ikaros Marvin A Payne. World J Biol Chem 2011; 2:161-6. [PMID: 21765982 PMCID: PMC3135863 DOI: 10.4331/wjbc.v2.i6.161] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/06/2011] [Accepted: 05/13/2011] [Indexed: 02/05/2023] Open
Abstract
The zinc finger motif was used as a vehicle for the initial discovery of Ikaros in the context of T-cell differentiation and has been central to all subsequent analyses of Ikaros function. The Ikaros gene is alternately spliced to produce several isoforms that confer diversity of function and consequently have complicated analysis of the function of Ikaros in vivo. Key features of Ikaros in vivo function are associated with six C2H2 zinc fingers; four of which are alternately incorporated in the production of the various Ikaros isoforms. Although no complete structures are available for the Ikaros protein or any of its family members, considerable evidence has accumulated about the structure of zinc fingers and the role that this structure plays in the functions of the Ikaros family of proteins. This review summarizes the structural aspects of Ikaros zinc fingers, individually, and in tandem to provide a structural context for Ikaros function and to provide a structural basis to inform the design of future experiments with Ikaros and its family members.
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Affiliation(s)
- Marvin A Payne
- Department of Chemistry and Biochemistry, La Sierra University, 4500 Riverwalk Parkway, Riverside, CA, USA
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28
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Dixit PD, Asthagiri D. An Elastic-Network-Based Local Molecular Field Analysis of Zinc Finger Proteins. J Phys Chem B 2011; 115:7374-82. [DOI: 10.1021/jp200244r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Purushottam D. Dixit
- Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - D. Asthagiri
- Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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29
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Jung HH, Jung HJ, Milescu M, Lee CW, Lee S, Lee JY, Eu YJ, Kim HH, Swartz KJ, Kim JI. Structure and orientation of a voltage-sensor toxin in lipid membranes. Biophys J 2010; 99:638-46. [PMID: 20643084 DOI: 10.1016/j.bpj.2010.04.061] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 04/16/2010] [Accepted: 04/20/2010] [Indexed: 10/19/2022] Open
Abstract
Amphipathic protein toxins from tarantula venom inhibit voltage-activated potassium (Kv) channels by binding to a critical helix-turn-helix motif termed the voltage sensor paddle. Although these toxins partition into membranes to bind the paddle motif, their structure and orientation within the membrane are unknown. We investigated the interaction of a tarantula toxin named SGTx with membranes using both fluorescence and NMR spectroscopy. Depth-dependent fluorescence-quenching experiments with brominated lipids suggest that Trp30 in SGTx is positioned approximately 9 A from the center of the bilayer. NMR spectra reveal that the inhibitor cystine knot structure of the toxin does not radically change upon membrane partitioning. Transferred cross-saturation NMR experiments indicate that the toxin's hydrophobic protrusion contacts the hydrophobic core of the membrane, whereas most surrounding polar residues remain at interfacial regions of the bilayer. The inferred orientation of the toxin reveals a twofold symmetry in the arrangement of basic and hydrophobic residues, a feature that is conserved among tarantula toxins. These results have important implications for regions of the toxin involved in recognizing membranes and voltage-sensor paddles, and for the mechanisms by which tarantula toxins alter the activity of different types of ion channels.
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Affiliation(s)
- Hyun Ho Jung
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju, Korea
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30
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Lee S, Doddapaneni K, Hogue A, McGhee L, Meyers S, Wu Z. Solution Structure of Gfi-1 Zinc Domain Bound to Consensus DNA. J Mol Biol 2010; 397:1055-66. [DOI: 10.1016/j.jmb.2010.02.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 02/02/2010] [Accepted: 02/04/2010] [Indexed: 01/29/2023]
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31
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Hatayama M, Aruga J. Characterization of the tandem CWCH2 sequence motif: a hallmark of inter-zinc finger interactions. BMC Evol Biol 2010; 10:53. [PMID: 20167128 PMCID: PMC2837044 DOI: 10.1186/1471-2148-10-53] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 02/19/2010] [Indexed: 11/11/2022] Open
Abstract
Background The C2H2 zinc finger (ZF) domain is widely conserved among eukaryotic proteins. In Zic/Gli/Zap1 C2H2 ZF proteins, the two N-terminal ZFs form a single structural unit by sharing a hydrophobic core. This structural unit defines a new motif comprised of two tryptophan side chains at the center of the hydrophobic core. Because each tryptophan residue is located between the two cysteine residues of the C2H2 motif, we have named this structure the tandem CWCH2 (tCWCH2) motif. Results Here, we characterized 587 tCWCH2-containing genes using data derived from public databases. We categorized genes into 11 classes including Zic/Gli/Glis, Arid2/Rsc9, PacC, Mizf, Aebp2, Zap1/ZafA, Fungl, Zfp106, Twincl, Clr1, and Fungl-4ZF, based on sequence similarity, domain organization, and functional similarities. tCWCH2 motifs are mostly found in organisms belonging to the Opisthokonta (metazoa, fungi, and choanoflagellates) and Amoebozoa (amoeba, Dictyostelium discoideum). By comparison, the C2H2 ZF motif is distributed widely among the eukaryotes. The structure and organization of the tCWCH2 motif, its phylogenetic distribution, and molecular phylogenetic analysis suggest that prototypical tCWCH2 genes existed in the Opisthokonta ancestor. Within-group or between-group comparisons of the tCWCH2 amino acid sequence identified three additional sequence features (site-specific amino acid frequencies, longer linker sequence between two C2H2 ZFs, and frequent extra-sequences within C2H2 ZF motifs). Conclusion These features suggest that the tCWCH2 motif is a specialized motif involved in inter-zinc finger interactions.
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Affiliation(s)
- Minoru Hatayama
- Laboratory for Behavioral and Developmental Disorders, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0198, Japan
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32
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Laity JH, Feng LS. Preparation and zinc-binding properties of multi-fingered zinc-sensing domains. Methods Mol Biol 2010; 649:411-35. [PMID: 20680850 DOI: 10.1007/978-1-60761-753-2_26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cys(2)His(2) zinc finger proteins (ZFPs) adopt a highly conserved betabetaalpha-fold, which is stabilized by tetrahedral coordination of a central zinc ion by two cysteine and two histidine residues. Although the function of most zinc fingers is sequence-specific DNA binding, other roles such as zinc sensing have been identified. Here, methods are described to produce micromole quantities of zinc-sensing zinc finger domains from the Zap1 (two zinc fingers) and MTF-1 (six zinc fingers) transcription factors. Procedures are outlined to isolate recombinant zinc finger proteins from a bacterial expression system that generates both soluble intracellular (Zap1) and insoluble inclusion body (MTF-1) forms. Isolated proteins are reduced and subsequently HPLC purified at low pH and lyophilized, which generates proteins that are ideal for zinc-binding studies or metal substitution studies and stable during long-term storage. NMR and calorimetric methods are described to measure relative and individual zinc ion affinities in multi-fingered proteins, which is an essential step in unraveling the zinc-sensing mechanism of MTF-1 and Zap1.
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Affiliation(s)
- John H Laity
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO, USA
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33
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Trbovic N, Cho JH, Abel R, Friesner RA, Rance M, Palmer AG. Protein side-chain dynamics and residual conformational entropy. J Am Chem Soc 2009; 131:615-22. [PMID: 19105660 DOI: 10.1021/ja806475k] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Changes in residual conformational entropy of proteins can be significant components of the thermodynamics of folding and binding. Nuclear magnetic resonance (NMR) spin relaxation is the only experimental technique capable of probing local protein entropy, by inference from local internal conformational dynamics. To assess the validity of this approach, the picosecond-to-nanosecond dynamics of the arginine side-chain N(epsilon)-H(epsilon) bond vectors of Escherichia coli ribonuclease H (RNase H) were determined by NMR spin relaxation and compared to the mechanistic detail provided by molecular dynamics (MD) simulations. The results indicate that arginine N(epsilon) spin relaxation primarily reflects persistence of guanidinium salt bridges and correlates well with simulated side-chain conformational entropy. In particular cases, the simulations show that the aliphatic part of the arginine side chain can retain substantial disorder while the guanidinium group maintains its salt bridges; thus, the N(epsilon)-H(epsilon) bond-vector orientation is conserved and side-chain flexibility is concealed from N(epsilon) spin relaxation. The MD simulations and an analysis of a rotamer library suggest that dynamic decoupling of the terminal moiety from the remainder of the side chain occurs for all five amino acids with more than two side-chain dihedral angles (R, K, E, Q, and M). Dynamic decoupling thus may represent a general biophysical strategy for minimizing the entropic penalties of folding and binding.
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Affiliation(s)
- Nikola Trbovic
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA
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Estrada DF, Boudreaux DM, Zhong D, St Jeor SC, De Guzman RN. The Hantavirus Glycoprotein G1 Tail Contains Dual CCHC-type Classical Zinc Fingers. J Biol Chem 2009; 284:8654-60. [PMID: 19179334 DOI: 10.1074/jbc.m808081200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Hantaviruses are distributed worldwide and can cause a hemorrhagic fever or a cardiopulmonary syndrome in humans. Mature virions consist of RNA genome, nucleocapsid protein, RNA polymerase, and two transmembrane glycoproteins, G1 and G2. The ectodomain of G1 is surface-exposed; however, it has a 142-residue C-terminal cytoplasmic tail that plays important roles in viral assembly and host-pathogen interaction. Here we show by NMR, circular dichroism spectroscopy, and mutagenesis that a highly conserved cysteine/histidine-rich region in the G1 tail of hantaviruses forms two CCHC-type classical zinc fingers. Unlike classical zinc fingers, however, the two G1 zinc fingers are intimately joined together, forming a compact domain with a unique fold. We discuss the implication of the hantaviral G1 zinc fingers in viral assembly and host-pathogen interaction.
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Affiliation(s)
- D Fernando Estrada
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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Emerson RO, Thomas JH. Adaptive evolution in zinc finger transcription factors. PLoS Genet 2009; 5:e1000325. [PMID: 19119423 PMCID: PMC2604467 DOI: 10.1371/journal.pgen.1000325] [Citation(s) in RCA: 220] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Accepted: 12/02/2008] [Indexed: 01/10/2023] Open
Abstract
The majority of human genes are conserved among mammals, but some gene families have undergone extensive expansion in particular lineages. Here, we present an evolutionary analysis of one such gene family, the poly–zinc-finger (poly-ZF) genes. The human genome encodes approximately 700 members of the poly-ZF family of putative transcriptional repressors, many of which have associated KRAB, SCAN, or BTB domains. Analysis of the gene family across the tree of life indicates that the gene family arose from a small ancestral group of eukaryotic zinc-finger transcription factors through many repeated gene duplications accompanied by functional divergence. The ancestral gene family has probably expanded independently in several lineages, including mammals and some fishes. Investigation of adaptive evolution among recent paralogs using dN/dS analysis indicates that a major component of the selective pressure acting on these genes has been positive selection to change their DNA-binding specificity. These results suggest that the poly-ZF genes are a major source of new transcriptional repression activity in humans and other primates. Gene families, arising by the repeated duplication and diversification of existing genes, are a pervasive feature of the genomes of higher organisms. In this study, we analyze the evolutionary history of one of the largest gene families in humans, the poly–zinc-finger genes. Each poly–zinc-finger gene is thought to act by regulating the expression levels of one or more other genes, but the ultimate function and purpose of most poly–zinc-finger genes is unknown. We have found that the poly–zinc-finger gene family has been growing rapidly in many lineages including the human lineage, and that evolution has favored the creation of new poly–zinc-finger genes that have different DNA targets than the genes from which they were derived. These results suggest that the emergence of new and different poly–zinc-finger genes has probably been important in the evolution of humans and many other animal species.
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Affiliation(s)
- Ryan O. Emerson
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - James H. Thomas
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Abstract
This overview provides an illustrated, comprehensive survey of some commonly observed protein‐fold families and structural motifs, chosen for their functional significance. It opens with descriptions and definitions of the various elements of protein structure and associated terminology. Following is an introduction into web‐based structural bioinformatics that includes surveys of interactive web servers for protein fold or domain annotation, protein‐structure databases, protein‐structure‐classification databases, structural alignments of proteins, and molecular graphics programs available for personal computers. The rest of the overview describes selected families of protein folds in terms of their secondary, tertiary, and quaternary structural arrangements, including ribbon‐diagram examples, tables of representative structures with references, and brief explanations pointing out their respective biological and functional significance.
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Affiliation(s)
- Peter D Sun
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
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Rothfels K, Rowland O, Segall J. Zinc fingers 1 and 7 of yeast TFIIIA are essential for assembly of a functional transcription complex on the 5 S RNA gene. Nucleic Acids Res 2007; 35:4869-81. [PMID: 17626045 PMCID: PMC1950542 DOI: 10.1093/nar/gkm517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The binding of transcription factor (TF) IIIA to the internal control region of the 5 S RNA gene is the first step in the assembly of a DNA–TFIIIA–TFIIIC– TFIIIB transcription complex, which promotes accurate transcription by RNA polymerase III. With the use of mutations that are predicted to disrupt the folding of a zinc finger, we have examined the roles of zinc fingers 1 through 7 of yeast TFIIIA in the establishment of a functional transcription complex both in vitro and in vivo. Our data indicate that, in addition to their role in DNA binding, the first and seventh zinc fingers contribute other essential roles in the assembly of an active transcription complex. Alanine-scanning mutagenesis identified residues within zinc finger 1 that are not required for DNA binding but are required for incorporation of TFIIIC into the TFIIIA–DNA complex. Although disruption of zinc finger 2 or 3 had a deleterious effect on the activity of TFIIIA both in vitro and in vivo, we found that increasing the level of their in vivo expression allowed these mutant proteins to support cell viability. Disruption of zinc fingers 4, 5 or 6 had minimal effect on the DNA binding and TF activities of TFIIIA.
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Affiliation(s)
- Karen Rothfels
- Department of Biochemistry and Department of Molecular and Medical Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Owen Rowland
- Department of Biochemistry and Department of Molecular and Medical Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Jacqueline Segall
- Department of Biochemistry and Department of Molecular and Medical Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8
- *To whom correspondence should be addressed.1 416 978 49811 416 978 8548
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López-Viñas E, Bentebibel A, Gurunathan C, Morillas M, de Arriaga D, Serra D, Asins G, Hegardt FG, Gómez-Puertas P. Definition by functional and structural analysis of two malonyl-CoA sites in carnitine palmitoyltransferase 1A. J Biol Chem 2007; 282:18212-18224. [PMID: 17452323 DOI: 10.1074/jbc.m700885200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Carnitine palmitoyltransferase 1 (CPT1) catalyzes the conversion of palmitoyl-CoA to palmitoylcarnitine in the presence of l-carnitine, thus facilitating the entry of fatty acids to mitochondria, in a process that is physiologically inhibited by malonyl-CoA. To examine the mechanism of CPT1 liver isoform (CPT1A) inhibition by malonyl-CoA, we constructed an in silico model of both its NH2- and COOH-terminal domains. Two malonyl-CoA binding sites were found. One of these, the "CoA site" or "A site," is involved in the interactions between NH2- and COOH-terminal domains and shares the acyl-CoA hemitunnel. The other, the "opposite-to-CoA site" or "O site," is on the opposite side of the enzyme, in the catalytic channel. The two sites share the carnitine-binding locus. To prevent the interaction between NH2- and COOH-terminal regions, we produced CPT1A E26K and K561E mutants. A double mutant E26K/K561E (swap), which was expected to conserve the interaction, was also produced. Inhibition assays showed a 12-fold decrease in the sensitivity (IC50) toward malonyl-CoA for CPT1A E26K and K561E single mutants, whereas swap mutant reverts to wild-type IC50 value. We conclude that structural interaction between both domains is critical for enzyme sensitivity to malonyl-CoA inhibition at the "A site." The location of the "O site" for malonyl-CoA binding was supported by inhibition assays of expressed R243T mutant. The model is also sustained by kinetic experiments that indicated linear mixed type malonyl-CoA inhibition for carnitine. Malonyl-CoA alters the affinity of carnitine, and there appears to be an exponential inverse relation between carnitine Km and malonyl-CoA IC50.
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Affiliation(s)
- Eduardo López-Viñas
- Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Cantoblanco, E-28049 Madrid, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Assia Bentebibel
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Chandrashekaran Gurunathan
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Montserrat Morillas
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Dolores de Arriaga
- Departamento de Biología Molecular, Universidad de León, E-24071 León, Spain
| | - Dolors Serra
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Guillermina Asins
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Fausto G Hegardt
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain.
| | - Paulino Gómez-Puertas
- Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Cantoblanco, E-28049 Madrid, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
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Segal DJ, Crotty JW, Bhakta MS, Barbas CF, Horton NC. Structure of Aart, a designed six-finger zinc finger peptide, bound to DNA. J Mol Biol 2006; 363:405-21. [PMID: 16963084 DOI: 10.1016/j.jmb.2006.08.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Revised: 08/08/2006] [Accepted: 08/08/2006] [Indexed: 11/20/2022]
Abstract
Cys2-His2 zinc fingers are one of the most common types of DNA-binding domains. Modifications to zinc-finger binding specificity have recently enabled custom DNA-binding proteins to be designed to a wide array of target sequences. We present here a 1.96 A structure of Aart, a designed six-zinc finger protein, bound to a consensus DNA target site. This is the first structure of a designed protein with six fingers, and was intended to provide insights into the unusual affinity and specificity characteristics of this protein. Most protein-DNA contacts were found to be consistent with expectations, while others were unanticipated or insufficient to explain specificity. Several were unexpectedly mediated by glycerol, water molecules or amino acid-base stacking interactions. These results challenge some conventional concepts of recognition, particularly the finding that triplets containing 5'A, C, or T are typically not specified by direct interaction with the amino acid in position 6 of the recognition helix.
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Affiliation(s)
- David J Segal
- UC Davis Genome Center and Department of Pharmacology, University of California, Davis, CA 95616, USA.
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Liu J, Perumal NB, Oldfield CJ, Su EW, Uversky VN, Dunker AK. Intrinsic disorder in transcription factors. Biochemistry 2006; 45:6873-88. [PMID: 16734424 PMCID: PMC2538555 DOI: 10.1021/bi0602718] [Citation(s) in RCA: 548] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intrinsic disorder (ID) is highly abundant in eukaryotes, which reflect the greater need for disorder-associated signaling and transcriptional regulation in nucleated cells. Although several well-characterized examples of intrinsically disordered proteins in transcriptional regulation have been reported, no systematic analysis has been reported so far. To test for the general prevalence of intrinsic disorder in transcriptional regulation, we used the predictor of natural disorder regions (PONDR) to analyze the abundance of intrinsic disorder in three transcription factor datasets and two control sets. This analysis revealed that from 94.13 to 82.63% of transcription factors possess extended regions of intrinsic disorder, relative to 54.51 and 18.64% of the proteins in two control datasets, which indicates the significant prevalence of intrinsic disorder in transcription factors. This propensity of transcription factors to intrinsic disorder was confirmed by cumulative distribution function analysis and charge-hydropathy plots. The amino acid composition analysis showed that all three transcription factor datasets were substantially depleted in order-promoting residues and significantly enriched in disorder-promoting residues. Our analysis of the distribution of disorder within the transcription factor datasets revealed that (a) the AT-hooks and basic regions of transcription factor DNA-binding domains are highly disordered; (b) the degree of disorder in transcription factor activation regions is much higher than that in DNA-binding domains; (c) the degree of disorder is significantly higher in eukaryotic transcription factors than in prokaryotic transcription factors; and (d) the level of alpha-MoRF (molecular recognition feature) prediction is much higher in transcription factors. Overall, our data reflected the fact that eukaryotes with well-developed gene transcription machinery require transcription factor flexibility to be more efficient.
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Affiliation(s)
- Jiangang Liu
- School of Informatics, Indiana University – Purdue University Indianapolis, 535 West Michigan St., Indianapolis, IN 46202, USA
- Bioinformatics Group, Lilly Research Laboratories, Eli Lilly and Company, DC GL54, Greenfield, IN 46140, USA
| | - Narayanan B. Perumal
- School of Informatics, Indiana University – Purdue University Indianapolis, 535 West Michigan St., Indianapolis, IN 46202, USA
| | - Christopher J. Oldfield
- School of Informatics, Indiana University – Purdue University Indianapolis, 535 West Michigan St., Indianapolis, IN 46202, USA
- Department of Biochemistry and Molecular Biology, and the Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, 714 N Senate Ave, suite 250, Indianapolis, IN 46202, USA
| | - Eric W. Su
- Bioinformatics Group, Lilly Research Laboratories, Eli Lilly and Company, DC GL54, Greenfield, IN 46140, USA
| | - Vladimir N. Uversky
- Department of Biochemistry and Molecular Biology, and the Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, 714 N Senate Ave, suite 250, Indianapolis, IN 46202, USA
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
- Molecular Kinetics, Inc., 6201 La Pas Trail, Suite 160, Indianapolis, Indiana 46268, USA
- To whom correspondence should be addressed at Center for Computational Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, School of Medicine, Indiana University - Purdue University at Indianapolis, 714 N. Senate St., Suite 250, Indianapolis, IN 46202. Phone: 317-278-9650; fax: 317-278-9217; E-mail:
| | - A. Keith Dunker
- School of Informatics, Indiana University – Purdue University Indianapolis, 535 West Michigan St., Indianapolis, IN 46202, USA
- Department of Biochemistry and Molecular Biology, and the Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, 714 N Senate Ave, suite 250, Indianapolis, IN 46202, USA
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Li Y, Kimura T, Laity JH, Andrews GK. The zinc-sensing mechanism of mouse MTF-1 involves linker peptides between the zinc fingers. Mol Cell Biol 2006; 26:5580-7. [PMID: 16847313 PMCID: PMC1592782 DOI: 10.1128/mcb.00471-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 05/06/2006] [Accepted: 05/20/2006] [Indexed: 11/20/2022] Open
Abstract
Mouse metal response element-binding transcription factor-1 (MTF-1) regulates the transcription of genes in response to a variety of stimuli, including exposure to zinc or cadmium, hypoxia, and oxidative stress. Each of these stresses may increase labile cellular zinc, leading to nuclear translocation, DNA binding, and transcriptional activation of metallothionein genes (MT genes) by MTF-1. Several lines of evidence suggest that the highly conserved six-zinc finger DNA-binding domain of MTF-1 also functions as a zinc-sensing domain. In this study, we investigated the potential role of the peptide linkers connecting the four N-terminal zinc fingers of MTF-1 in their zinc-sensing function. Each of these three linkers is unique, completely conserved among all known vertebrate MTF-1 orthologs, and different from the canonical Cys2His2 zinc finger TGEKP linker sequence. Replacing the RGEYT linker between zinc fingers 1 and 2 with TGEKP abolished the zinc-sensing function of MTF-1, resulting in constitutive DNA binding, nuclear translocation, and transcriptional activation of the MT-I gene. In contrast, swapping the TKEKP linker between fingers 2 and 3 with TGEKP had little effect on the metal-sensing functions of MTF-1, whereas swapping the canonical linker for the shorter TGKT linker between fingers 3 and 4 rendered MTF-1 less sensitive to zinc-dependent activation both in vivo and in vitro. These observations suggest a mechanism by which physiological concentrations of accessible cellular zinc affect MTF-1 activity. Zinc may modulate highly specific, linker-mediated zinc finger interactions in MTF-1, thus affecting its zinc- and DNA-binding activities, resulting in translocation to the nucleus and binding to the MT-I gene promoter.
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Affiliation(s)
- Yong Li
- Department of Biochemistry and Molecular Biology, Mail Stop 3030, University of Kansas Medical Center, 39th and Rainbow Blvd., Kansas City, KS 66160-7421, USA
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Carneiro FRG, Silva TCL, Alves AC, Haline-Vaz T, Gozzo FC, Zanchin NIT. Spectroscopic characterization of the tumor antigen NY-REN-21 and identification of heterodimer formation with SCAND1. Biochem Biophys Res Commun 2006; 343:260-8. [PMID: 16540086 DOI: 10.1016/j.bbrc.2006.02.140] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Accepted: 02/23/2006] [Indexed: 11/23/2022]
Abstract
Human NY-REN-21 is a C2H2 type multi-finger protein, with a SCAN domain in the N-terminal region and a predicted coil central region. It represents a putative ortholog of mouse ZFP38, a transcriptional factor that recognizes a bipartite DNA motif and is unable to form homodimers. As shown in this work, NY-REN-21 contains a SCAN domain able to form homodimers and a central region that behaves as an intrinsically disordered protein. The SCAN domain is found in 71 human proteins and its ability to form homo- and heterodimers widens the number of genes that are regulated by this group of transcription factors. NY-REN-21 interaction with SCAND1 was identified using the yeast two-hybrid system and confirmed using recombinant proteins. SCAND1 is a truncated SCAN box protein, lacking the zinc finger region and the NY-REN-21/SCAND1 heterodimer is asymmetric concerning the DNA binding region. This result indicates that NY-REN-21 can function either as a homodimer or as a heterodimer with SCAND1.
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Affiliation(s)
- Flávia R G Carneiro
- Center for Structural Molecular Biology, Brazilian Synchrotron Light Laboratory, LNLS, Rua Giuseppe Maximo Scolfaro 10000, P.O. Box 6192, CEP 13084-971, Campinas SP, Brazil
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Lugtenberg D, Yntema HG, Banning MJG, Oudakker AR, Firth HV, Willatt L, Raynaud M, Kleefstra T, Fryns JP, Ropers HH, Chelly J, Moraine C, Gecz J, van Reeuwijk J, Nabuurs SB, de Vries BBA, Hamel BCJ, de Brouwer APM, van Bokhoven H. ZNF674: a new kruppel-associated box-containing zinc-finger gene involved in nonsyndromic X-linked mental retardation. Am J Hum Genet 2006; 78:265-78. [PMID: 16385466 PMCID: PMC1380234 DOI: 10.1086/500306] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Accepted: 11/17/2005] [Indexed: 01/13/2023] Open
Abstract
Array-based comparative genomic hybridization has proven to be successful in the identification of genetic defects in disorders involving mental retardation. Here, we studied a patient with learning disabilities, retinal dystrophy, and short stature. The family history was suggestive of an X-linked contiguous gene syndrome. Hybridization of full-coverage X-chromosomal bacterial artificial chromosome arrays revealed a deletion of ~1 Mb in Xp11.3, which harbors RP2, SLC9A7, CHST7, and two hypothetical zinc-finger genes, ZNF673 and ZNF674. These genes were analyzed in 28 families with nonsyndromic X-linked mental retardation (XLMR) that show linkage to Xp11.3; the analysis revealed a nonsense mutation, p.E118X, in the coding sequence of ZNF674 in one family. This mutation is predicted to result in a truncated protein containing the Kruppel-associated box domains but lacking the zinc-finger domains, which are crucial for DNA binding. We characterized the complete ZNF674 gene structure and subsequently tested an additional 306 patients with XLMR for mutations by direct sequencing. Two amino acid substitutions, p.T343M and p.P412L, were identified that were not found in unaffected individuals. The proline at position 412 is conserved between species and is predicted by molecular modeling to reduce the DNA-binding properties of ZNF674. The p.T343M transition is probably a polymorphism, because the homologous ZNF674 gene in chimpanzee has a methionine at that position. ZNF674 belongs to a cluster of seven highly related zinc-finger genes in Xp11, two of which (ZNF41 and ZNF81) were implicated previously in XLMR. Identification of ZNF674 as the third XLMR gene in this cluster may indicate a common role for these zinc-finger genes that is crucial to human cognitive functioning.
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Affiliation(s)
- Dorien Lugtenberg
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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44
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Baird-Titus JM, Clark-Baldwin K, Dave V, Caperelli CA, Ma J, Rance M. The solution structure of the native K50 Bicoid homeodomain bound to the consensus TAATCC DNA-binding site. J Mol Biol 2005; 356:1137-51. [PMID: 16406070 DOI: 10.1016/j.jmb.2005.12.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2005] [Revised: 11/30/2005] [Accepted: 12/02/2005] [Indexed: 11/29/2022]
Abstract
The solution structure of the homeodomain of the Drosophila morphogenic protein Bicoid (Bcd) complexed with a TAATCC DNA site is described. Bicoid is the only known protein that uses a homeodomain to regulate translation, as well as transcription, by binding to both RNA and DNA during early Drosophila development; in addition, the Bcd homeodomain can recognize an array of different DNA sites. The dual functionality and broad recognition capabilities signify that the Bcd homeodomain may possess unique structural/dynamic properties. Bicoid is the founding member of the K50 class of homeodomain proteins, containing a lysine residue at the critical 50th position (K50) of the homeodomain sequence, a residue required for DNA and RNA recognition; Bcd also has an arginine residue at the 54th position (R54), which is essential for RNA recognition. Bcd is the only known homeodomain with the K50/R54 combination of residues. The Bcd structure indicates that this homeodomain conforms to the conserved topology of the homeodomain motif, but exhibits a significant variation from other homeodomain structures at the end of helix 1. A key result is the observation that the side-chains of the DNA-contacting residues K50, N51 and R54 all show strong signs of flexibility in the protein-DNA interface. This finding is supportive of the adaptive-recognition theory of protein-DNA interactions.
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Affiliation(s)
- Jamie M Baird-Titus
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Medical Sciences Building, Cincinnati, OH 45267-0524, USA
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45
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Potter BM, Feng LS, Parasuram P, Matskevich VA, Wilson JA, Andrews GK, Laity JH. The six zinc fingers of metal-responsive element binding transcription factor-1 form stable and quasi-ordered structures with relatively small differences in zinc affinities. J Biol Chem 2005; 280:28529-40. [PMID: 16055450 DOI: 10.1074/jbc.m505217200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Six Cys(2)His(2) zinc fingers (F1-6) comprise the DNA binding domain of metal-responsive element binding transcription factor-1 (MTF-1). F1-6 is necessary for basal and zinc-induced expression of metallothionein genes. Analysis of NMR structural and dynamic data for an F1-6 protein construct demonstrates that each zinc finger adopts a stable betabetaalpha fold in the presence of stoichiometric Zn(II), provided that all cysteine ligands are in a reduced state. Parallel studies of protein constructs spanning the four N-terminal core DNA binding fingers (F1-4) and two C-terminal low DNA affinity fingers (F5-6) reveal similar stable zinc finger structures. In both the F1-6 and F5-6 proteins, the finger 5 cysteines were found to readily oxidize at neutral pH. Detailed spectral density and hydrodynamic analysis of (15)N relaxation data revealed quasi-ordered anisotropic rotational diffusion properties of the six F1-6 zinc fingers that could influence MTF-1 DNA binding function. A more general effect on the rotational diffusion properties of Cys(2)His(2) zinc fingers was also uncovered that is dependent upon the position of each finger within multifinger domains. Analysis of NMR (1)H-(15)N-heteronuclear single quantum coherence spectral peak intensities measured as a function of added Zn(II) in conjunction with Zn(II) binding modeling studies indicated that the Zn(II) affinities of all MTF-1 zinc fingers are within approximately 10-50-fold. These analyses further suggested that metal sensing by MTF-1 in eukaryotic cells involves multiple zinc fingers and occurs over a 100-fold or less range of accessible Zn(II) concentration.
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Affiliation(s)
- Belinda M Potter
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
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Murray KB, Taylor WR, Thornton JM. Toward the detection and validation of repeats in protein structure. Proteins 2005; 57:365-80. [PMID: 15340924 DOI: 10.1002/prot.20202] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We present a method called DAVROS to detect, localize, and validate repeating motifs in protein structure allowing for insertions and deletions. DAVROS uses the score matrix from a structural alignment program (SAP) to search for repeating motifs using an algorithm based on concepts from signal processing and the statistical properties of the alignments. The method was tested against a nonredundant Protein Data Bank, and each chain was assigned a score. For the top 50 chains ranked by score, 70% contain repeating motifs detected without error. These represent 14 types of fold covering alpha, beta, and alphabeta protein classes. A second data set comprising protein chains in different sequence families for triosephosphate isomerase (TIM) barrel, leucine-rich repeat (LRR), trefoil, and alpha-alpha barrel folds was used to assess the ability of DAVROS to detect all motifs within a specific fold. For the second test set, the percentage of motifs detected was highest for the LRR chains (88.7%) and least for the TIM barrels (60%). This variability results from the regularity of the LRR motif compared to the alphabeta units of the TIM barrel, which generally have many more indels. These reduce the strength of the repeat signal in the SAP matrix, making repeat detection more difficult.
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Affiliation(s)
- Kevin B Murray
- European Bioinformatics Institute, European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
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Brady KL, Ponnampalam SN, Bumbulis MJ, Setzer DR. Mutations in TFIIIA that increase stability of the TFIIIA-5 S rRNA gene complex: unusual effects on the kinetics of complex assembly and dissociation. J Biol Chem 2005; 280:26743-50. [PMID: 15888446 DOI: 10.1074/jbc.m502677200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have identified four mutations in Xenopus TFIIIA that increase the stability of TFIIIA-5 S rRNA gene complexes. In each case, the mutation has a relatively modest effect on equilibrium binding affinity. In three cases, these equilibrium binding effects can be ascribed primarily to decreases in the rate constant for protein-DNA complex dissociation. In the fourth case, however, a substitution of phenylalanine for the wild-type leucine at position 148 in TFIIIA results in much larger compensating changes in the kinetics of complex assembly and dissociation. The data support a model in which a relatively unstable population of complexes with multi-component dissociation kinetics forms rapidly; complexes then undergo a slow conformational change that results in very stable, kinetically homogeneous TFIIIA-DNA complexes. The L148F mutant protein acts as a particularly potent transcriptional activator when it is fused to the VP16 activation domain and expressed in yeast cells. Substitution of L148 to tyrosine or tryptophan produces an equally strong transcriptional activator. Substitution to histidine results in genetic and biochemical effects that are more modest than, but similar to, those observed with the L148F mutation. We propose that an amino acid with a planar side chain at position 148 can intercalate between adjacent base pairs in the intermediate element of the 5 S rRNA gene. Intercalation occurs slowly but results in a very stable DNA-protein complex. These results suggest that transcriptional activation by a cis-acting sequence element is largely dependent on the kinetic, rather than the thermodynamic, stability of the complex formed with an activator protein. Thus, transcriptional activation is dependent in large part on the lifetime of the activator-DNA complex rather than on binding site occupancy at steady state. Introduction of intercalating amino acids into zinc finger proteins may be a useful tool for producing artificial transcription factors with particularly high in vivo activity.
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Affiliation(s)
- Kristina L Brady
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Brady KL, Setzer DR. Is There a Dynamic DNA-Protein Interface in the Transcription Factor IIIA-5 S rRNA Gene Complex? J Biol Chem 2005; 280:16115-24. [PMID: 15713659 DOI: 10.1074/jbc.m414660200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Others have proposed that several amino acid side chains exhibit considerable conformational mobility at the DNA-protein interface in the transcription factor IIIA.5 S rRNA gene complex and that the rapid movements of these side chains permit them to make fluctuating contacts with adjacent bp in the DNA target site. This "dynamic interface" model makes biochemical predictions concerning the consequences of truncating specific amino acid side chains and the effects of these truncations on sequence selectivity in DNA binding. The model also makes predictions concerning the effects of DNA sequence context on the apparent energetic contributions to binding made by individual bp. We have tested these predictions, and our results are inconsistent with any significant energetic role being played by the contact of multiple bp by conformationally mobile amino acid side chains. They do, however, show that some individual amino acids affect the recognition of multiple bp through mechanisms other than direct interaction.
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Affiliation(s)
- Kristina L Brady
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
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Huang M, Krepkiy D, Hu W, Petering DH. Zn-, Cd-, and Pb-transcription factor IIIA: properties, DNA binding, and comparison with TFIIIA-finger 3 metal complexes. J Inorg Biochem 2005; 98:775-85. [PMID: 15134923 PMCID: PMC3516448 DOI: 10.1016/j.jinorgbio.2004.01.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 01/26/2004] [Accepted: 01/29/2004] [Indexed: 10/26/2022]
Abstract
Properties of the metal ion binding sites of Zn-transcription factor IIIA (TFIIIA) were investigated to understand the potential of this type of zinc finger to undergo reactions that remove Zn(2+) from the protein. Zn-TFIIIA was purified from E. coli containing the cloned sequence for Xenopus laevis oocyte TFIIIA and its stoichiometry of bound Zn(2+) was shown to depend on the details of the isolation process. The average dissociation constant of Zn(2+) in Zn-TFIIIIA was 10(-7). The dissociation constant for Zn-F3, the third finger from the N-terminus of TFIIIA, was 1.0 x 10(-8). The reactivity of Zn-TFIIIA with a series of metal binding ligands, including 2-carboxy-2'-hydroxy-5'-sulfoformazylbenzene (zincon), 4-(2-pyridylazo)-resorcinol (PAR), and 3-ethoxy-2-oxo-butyraldehyde-bis-(N(4)-dimethylthiosemicarbazone) (H(2)KTSM(2)) revealed similar kinetics. The reactivity of PAR with Zn-TFIIIA declined substantially when the protein was bound to the internal control region (ICR) of the 5S ribosomal DNA. Both Cd(2+) and Pb(2+) disrupt TFIIIA binding to its cognate DNA sequence. The Pb(2+) dissociation constant of Pb-F3 was measured as 2.5 x 10(-8). According to NMR spectroscopy, F3 does not fold into a regular conformation in the presence of Pb(2+).
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Spectroscopic Studies on Interaction of Protoberberines with the Deoxyoligonucleotide d(GCCGTCGTTTTACA)2. B KOREAN CHEM SOC 2004. [DOI: 10.5012/bkcs.2004.25.10.1559] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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