1
|
Fukushima T, Gupta S, Rad B, Cornejo JA, Petzold CJ, Chan LJG, Mizrahi RA, Ralston CY, Ajo-Franklin CM. The Molecular Basis for Binding of an Electron Transfer Protein to a Metal Oxide Surface. J Am Chem Soc 2017; 139:12647-12654. [DOI: 10.1021/jacs.7b06560] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Tatsuya Fukushima
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Sayan Gupta
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Behzad Rad
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jose A. Cornejo
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Christopher J. Petzold
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Leanne Jade G. Chan
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Rena A. Mizrahi
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Corie Y. Ralston
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Caroline M. Ajo-Franklin
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| |
Collapse
|
2
|
Gupta S, Feng J, Chan LJG, Petzold CJ, Ralston CY. Synchrotron X-ray footprinting as a method to visualize water in proteins. JOURNAL OF SYNCHROTRON RADIATION 2016; 23:1056-69. [PMID: 27577756 PMCID: PMC5006651 DOI: 10.1107/s1600577516009024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 06/03/2016] [Indexed: 05/23/2023]
Abstract
The vast majority of biomolecular processes are controlled or facilitated by water interactions. In enzymes, regulatory proteins, membrane-bound receptors and ion-channels, water bound to functionally important residues creates hydrogen-bonding networks that underlie the mechanism of action of the macromolecule. High-resolution X-ray structures are often difficult to obtain with many of these classes of proteins because sample conditions, such as the necessity of detergents, often impede crystallization. Other biophysical techniques such as neutron scattering, nuclear magnetic resonance and Fourier transform infrared spectroscopy are useful for studying internal water, though each has its own advantages and drawbacks, and often a hybrid approach is required to address important biological problems associated with protein-water interactions. One major area requiring more investigation is the study of bound water molecules which reside in cavities and channels and which are often involved in both the structural and functional aspects of receptor, transporter and ion channel proteins. In recent years, significant progress has been made in synchrotron-based radiolytic labeling and mass spectroscopy techniques for both the identification of bound waters and for characterizing the role of water in protein conformational changes at a high degree of spatial and temporal resolution. Here the latest developments and future capabilities of this method for investigating water-protein interactions and its synergy with other synchrotron-based methods are discussed.
Collapse
Affiliation(s)
- Sayan Gupta
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jun Feng
- Experimental Systems, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Leanne Jade G. Chan
- Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Christopher J. Petzold
- Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Corie Y. Ralston
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| |
Collapse
|
3
|
Abstract
Traditionally eukaryotes exclusive cytoskeleton has been found in bacteria and other prokaryotes. FtsZ, MreB and CreS are bacterial counterpart of eukaryotic tubulin, actin filaments and intermediate filaments, respectively. FtsZ can assemble to a Z-ring at the cell division site, regulate bacterial cell division; MreB can form helical structure, and involve in maintaining cell shape, regulating chromosome segregation; CreS, found in Caulobacter crescentus (C. crescentus), can form curve or helical filaments in intracellular membrane. CreS is crucial for cell morphology maintenance. There are also some prokaryotic unique cytoskeleton components playing crucial roles in cell division, chromosome segregation and cell morphology. The cytoskeleton components of Mycobacterium tuberculosis (M. tuberculosis), together with their dynamics during exposure to antibiotics are summarized in this article to provide insights into the unique organization of this formidable pathogen and druggable targets for new antibiotics.
Collapse
Affiliation(s)
- Huan Wang
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Longxiang Xie
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Hongping Luo
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Jianping Xie
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| |
Collapse
|
4
|
Heberle FA, Myles DAA, Katsaras J. Biomembranes research using thermal and cold neutrons. Chem Phys Lipids 2015; 192:41-50. [PMID: 26241882 DOI: 10.1016/j.chemphyslip.2015.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/25/2015] [Accepted: 07/27/2015] [Indexed: 01/26/2023]
Abstract
In 1932 James Chadwick discovered the neutron using a polonium source and a beryllium target (Chadwick, 1932). In a letter to Niels Bohr dated February 24, 1932, Chadwick wrote: "whatever the radiation from Be may be, it has most remarkable properties." Where it concerns hydrogen-rich biological materials, the "most remarkable" property is the neutron's differential sensitivity for hydrogen and its isotope deuterium. Such differential sensitivity is unique to neutron scattering, which unlike X-ray scattering, arises from nuclear forces. Consequently, the coherent neutron scattering length can experience a dramatic change in magnitude and phase as a result of resonance scattering, imparting sensitivity to both light and heavy atoms, and in favorable cases to their isotopic variants. This article describes recent biomembranes research using a variety of neutron scattering techniques.
Collapse
Affiliation(s)
- F A Heberle
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge, TN, 37831, United States; Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States
| | - D A A Myles
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge, TN, 37831, United States
| | - J Katsaras
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge, TN, 37831, United States; Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, United States.
| |
Collapse
|
5
|
Chaudhuri BN. Emerging applications of small angle solution scattering in structural biology. Protein Sci 2015; 24:267-76. [PMID: 25516491 PMCID: PMC4353354 DOI: 10.1002/pro.2624] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 12/05/2014] [Indexed: 12/12/2022]
Abstract
Small angle solution X-ray and neutron scattering recently resurfaced as powerful tools to address an array of biological problems including folding, intrinsic disorder, conformational transitions, macromolecular crowding, and self or hetero-assembling of biomacromolecules. In addition, small angle solution scattering complements crystallography, nuclear magnetic resonance spectroscopy, and other structural methods to aid in the structure determinations of multidomain or multicomponent proteins or nucleoprotein assemblies. Neutron scattering with hydrogen/deuterium contrast variation, or X-ray scattering with sucrose contrast variation to a certain extent, is a convenient tool for characterizing the organizations of two-component systems such as a nucleoprotein or a lipid-protein assembly. Time-resolved small and wide-angle solution scattering to study biological processes in real time, and the use of localized heavy-atom labeling and anomalous solution scattering for applications as FRET-like molecular rulers, are amongst promising newer developments. Despite the challenges in data analysis and interpretation, these X-ray/neutron solution scattering based approaches hold great promise for understanding a wide variety of complex processes prevalent in the biological milieu.
Collapse
Affiliation(s)
- Barnali N Chaudhuri
- Faculty of Life Sciences and Biotechnology, South Asian UniversityAkbar Bhawan, Chanakyapuri, New Delhi, India
| |
Collapse
|
6
|
Gupta S, Celestre R, Petzold CJ, Chance MR, Ralston C. Development of a microsecond X-ray protein footprinting facility at the Advanced Light Source. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:690-9. [PMID: 24971962 PMCID: PMC4073957 DOI: 10.1107/s1600577514007000] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 03/29/2014] [Indexed: 05/05/2023]
Abstract
X-ray footprinting (XF) is an important structural biology tool used to determine macromolecular conformations and dynamics of both nucleic acids and proteins in solution on a wide range of timescales. With the impending shut-down of the National Synchrotron Light Source, it is ever more important that this tool continues to be developed at other synchrotron facilities to accommodate XF users. Toward this end, a collaborative XF program has been initiated at the Advanced Light Source using the white-light bending-magnet beamlines 5.3.1 and 3.2.1. Accessibility of the microsecond time regime for protein footprinting is demonstrated at beamline 5.3.1 using the high flux density provided by a focusing mirror in combination with a micro-capillary flow cell. It is further reported that, by saturating samples with nitrous oxide, the radiolytic labeling efficiency is increased and the imprints of bound versus bulk water can be distinguished. These results both demonstrate the suitability of the Advanced Light Source as a second home for the XF experiment, and pave the way for obtaining high-quality structural data on complex protein samples and dynamics information on the microsecond timescale.
Collapse
Affiliation(s)
- Sayan Gupta
- Berkeley Center for Structural Biology, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Richard Celestre
- Experimental Systems, Advanced Light Source Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Christopher J. Petzold
- Joint BioEnergy Institute, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Mark R. Chance
- Center for Synchrotron Biosciences, Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Corie Ralston
- Berkeley Center for Structural Biology, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| |
Collapse
|
7
|
Heller WT, Urban VS, Lynn GW, Weiss KL, O'Neill HM, Pingali SV, Qian S, Littrell KC, Melnichenko YB, Buchanan MV, Selby DL, Wignall GD, Butler PD, Myles DA. The Bio-SANS instrument at the High Flux Isotope Reactor of Oak Ridge National Laboratory. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576714011285] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Small-angle neutron scattering (SANS) is a powerful tool for characterizing complex disordered materials, including biological materials. The Bio-SANS instrument of the High Flux Isotope Reactor of Oak Ridge National Laboratory (ORNL) is a high-flux low-background SANS instrument that is, uniquely among SANS instruments, dedicated to serving the needs of the structural biology and biomaterials communities as an open-access user facility. Here, the technical specifications and performance of the Bio-SANS are presented. Sample environments developed to address the needs of the user program of the instrument are also presented. Further, the isotopic labeling and sample preparation capabilities available in the Bio-Deuteration Laboratory for users of the Bio-SANS and other neutron scattering instruments at ORNL are described. Finally, a brief survey of research performed using the Bio-SANS is presented, which demonstrates the breadth of the research that the instrument's user community engages in.
Collapse
|
8
|
Bohon J, D’Mello R, Ralston C, Gupta S, Chance MR. Synchrotron X-ray footprinting on tour. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:24-31. [PMID: 24365913 PMCID: PMC3874017 DOI: 10.1107/s1600577513024715] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 09/04/2013] [Indexed: 05/22/2023]
Abstract
Synchrotron footprinting is a valuable technique in structural biology for understanding macromolecular solution-state structure and dynamics of proteins and nucleic acids. Although an extremely powerful tool, there is currently only a single facility in the USA, the X28C beamline at the National Synchrotron Light Source (NSLS), dedicated to providing infrastructure, technology development and support for these studies. The high flux density of the focused white beam and variety of specialized exposure environments available at X28C enables footprinting of highly complex biological systems; however, it is likely that a significant fraction of interesting experiments could be performed at unspecialized facilities. In an effort to investigate the viability of a beamline-flexible footprinting program, a standard sample was taken on tour around the nation to be exposed at several US synchrotrons. This work describes how a relatively simple and transportable apparatus can allow beamlines at the NSLS, CHESS, APS and ALS to be used for synchrotron footprinting in a general user mode that can provide useful results.
Collapse
Affiliation(s)
- Jen Bohon
- Center for Synchrotron Biosciences, Case Western Reserve University, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA
- Center for Proteomics and Bioinformatics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Correspondence e-mail:
| | - Rhijuta D’Mello
- Center for Synchrotron Biosciences, Case Western Reserve University, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA
- Center for Proteomics and Bioinformatics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Corie Ralston
- Berkeley Center for Structural Biology, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Sayan Gupta
- Berkeley Center for Structural Biology, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Mark R. Chance
- Center for Synchrotron Biosciences, Case Western Reserve University, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA
- Center for Proteomics and Bioinformatics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| |
Collapse
|
9
|
Topoisomerase I (TopA) is recruited to ParB complexes and is required for proper chromosome organization during Streptomyces coelicolor sporulation. J Bacteriol 2013; 195:4445-55. [PMID: 23913317 DOI: 10.1128/jb.00798-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Streptomyces species are bacteria that resemble filamentous fungi in their hyphal mode of growth and sporulation. In Streptomyces coelicolor, the conversion of multigenomic aerial hyphae into chains of unigenomic spores requires synchronized septation accompanied by segregation of tens of chromosomes into prespore compartments. The chromosome segregation is dependent on ParB protein, which assembles into an array of nucleoprotein complexes in the aerial hyphae. Here, we report that nucleoprotein ParB complexes are bound in vitro and in vivo by topoisomerase I, TopA, which is the only topoisomerase I homolog found in S. coelicolor. TopA cannot be eliminated, and its depletion inhibits growth and blocks sporulation. Surprisingly, sporulation in the TopA-depleted strain could be partially restored by deletion of parB. Furthermore, the formation of regularly spaced ParB complexes, which is a prerequisite for proper chromosome segregation and septation during the development of aerial hyphae, has been found to depend on TopA. We hypothesize that TopA is recruited to ParB complexes during sporulation, and its activity is required to resolve segregating chromosomes.
Collapse
|
10
|
Breyton C, Gabel F, Lethier M, Flayhan A, Durand G, Jault JM, Juillan-Binard C, Imbert L, Moulin M, Ravaud S, Härtlein M, Ebel C. Small angle neutron scattering for the study of solubilised membrane proteins. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2013; 36:71. [PMID: 23852580 DOI: 10.1140/epje/i2013-13071-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 04/22/2013] [Accepted: 05/16/2013] [Indexed: 06/02/2023]
Abstract
Small angle neutron scattering (SANS) is a powerful technique for investigating association states and conformational changes of biological macromolecules in solution. SANS is of particular interest for the study of the multi-component systems, as membrane protein complexes, for which in vitro characterisation and structure determination are often difficult. This article details the important physical properties of surfactants in view of small angle neutron scattering studies and the interest to deuterate membrane proteins for contrast variation studies. We present strategies for the production of deuterated membrane proteins and methods for quality control. We then review some studies on membrane proteins, and focus on the strategies to overcome the intrinsic difficulty to eliminate homogeneously the detergent or surfactant signal for solubilised membrane proteins, or that of lipids for membrane proteins inserted in liposomes.
Collapse
Affiliation(s)
- Cécile Breyton
- Univ. Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38027, Grenoble, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Ginda K, Bezulska M, Ziółkiewicz M, Dziadek J, Zakrzewska-Czerwińska J, Jakimowicz D. ParA ofMycobacterium smegmatisco-ordinates chromosome segregation with the cell cycle and interacts with the polar growth determinant DivIVA. Mol Microbiol 2013; 87:998-1012. [DOI: 10.1111/mmi.12146] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/24/2012] [Indexed: 11/29/2022]
Affiliation(s)
- Katarzyna Ginda
- Faculty of Biotechnology; University of Wrocław; Wrocław; Poland
| | - Martyna Bezulska
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy; Polish Academy of Sciences; Wrocław; Poland
| | | | - Jarosław Dziadek
- Medical Biology Institute; Polish Academy of Sciences; Lodowa 106; 93-232; Łódź; Poland
| | | | | |
Collapse
|
12
|
Qian S, Dean R, Urban VS, Chaudhuri BN. The internal organization of mycobacterial partition assembly: does the DNA wrap a protein core? PLoS One 2012; 7:e52690. [PMID: 23285150 PMCID: PMC3527565 DOI: 10.1371/journal.pone.0052690] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 11/20/2012] [Indexed: 11/18/2022] Open
Abstract
Before cell division in many bacteria, the ParBs spread on a large segment of DNA encompassing the origin-proximal parS site(s) to form the partition assembly that participates in chromosome segregation. Little is known about the structural organization of chromosomal partition assembly. We report solution X-ray and neutron scattering data characterizing the size parameters and internal organization of a nucleoprotein assembly formed by the mycobacterial chromosomal ParB and a 120-meric DNA containing a parS-encompassing region from the mycobacterial genome. The cross-sectional radii of gyration and linear mass density describing the rod-like ParB-DNA assembly were determined from solution scattering. A "DNA outside, protein inside" mode of partition assembly organization consistent with the neutron scattering hydrogen/deuterium contrast variation data is discussed. In this organization, the high scattering DNA is positioned towards the outer region of the partition assembly. The new results presented here provide a basis for understanding how ParBs organize the parS-proximal chromosome, thus setting the stage for further interactions with the DNA condensins, the origin tethering factors and the ParA.
Collapse
Affiliation(s)
- Shuo Qian
- Center for Structural Molecular Biology, Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Rebecca Dean
- Hauptman Woodward Institute, Buffalo, New York, United States of America
| | - Volker S. Urban
- Center for Structural Molecular Biology, Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Barnali N. Chaudhuri
- Hauptman Woodward Institute, Buffalo, New York, United States of America
- Department of Structural Biology, State University of New York, Buffalo, New York, United States of America
| |
Collapse
|
13
|
The evidence of large-scale DNA-induced compaction in the mycobacterial chromosomal ParB. J Mol Biol 2011; 413:901-7. [PMID: 21839743 DOI: 10.1016/j.jmb.2011.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 07/22/2011] [Accepted: 08/01/2011] [Indexed: 11/21/2022]
Abstract
The bacterial chromosome trafficking apparatus or the segrosome participates in the mitotic-like segregation of the chromosomes prior to cell division in several bacteria. ParB, which is the parS DNA-binding component of the segrosome, polymerizes on the parS-adjacent chromosome to form a nucleoprotein filament of unknown nature for the segregation function. We combined static light scattering, circular dichroism and small-angle X-ray scattering to present evidence that the apo form of the mycobacterial ParB forms an elongated dimer with intrinsically disordered regions as well as folded domains in solution. A comparison of the solution scattering of the apo and the parS-bound ParBs indicates a rather drastic compaction of the protein upon DNA binding. We propose that this binding-induced conformational transition is priming the ParB for polymerization on the DNA template.
Collapse
|