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dc.contributor.authorLi, Xiachuan Edward
dc.contributor.authorTobacman, Larry S.
dc.contributor.authorMun, Ji Young
dc.contributor.authorCraig, Roger W.
dc.contributor.authorFischer, Stefan
dc.contributor.authorLehman, William
dc.date2022-08-11T08:08:03.000
dc.date.accessioned2022-08-23T15:40:32Z
dc.date.available2022-08-23T15:40:32Z
dc.date.issued2011-02-16
dc.date.submitted2011-07-29
dc.identifier.citationBiophys J. 2011 Feb 16;100(4):1005-13. <a href="http://dx.doi.org/10.1016/j.bpj.2010.12.3697">Link to article on publisher's site</a>
dc.identifier.issn0006-3495 (Linking)
dc.identifier.doi10.1016/j.bpj.2010.12.3697
dc.identifier.pmid21320445
dc.identifier.urihttp://hdl.handle.net/20.500.14038/26424
dc.description.abstractElectron microscopy and fiber diffraction studies of reconstituted F-actin-tropomyosin filaments reveal the azimuthal position of end-to-end linked tropomyosin molecules on the surface of actin. However, the longitudinal z-position of tropomyosin along F-actin is still uncertain. Without this information, atomic models of F-actin-tropomyosin filaments, free of constraints imposed by troponin or other actin-binding proteins, cannot be formulated, and thus optimal interfacial contacts between actin and tropomyosin remain unknown. Here, a computational search assessing electrostatic interactions for multiple azimuthal locations, z-positions, and pseudo-rotations of tropomyosin on F-actin was performed. The information gleaned was used to localize tropomyosin on F-actin, yielding an atomic model characterized by protein-protein contacts that primarily involve clusters of basic amino acids on actin subdomains 1 and 3 juxtaposed against acidic residues on the successive quasi-repeating units of tropomyosin. A virtually identical model generated by docking F-actin and tropomyosin atomic structures into electron microscopy reconstructions of F-actin-tropomyosin validated the above solution. Here, the z-position of tropomyosin alongside F-actin was defined by matching the seven broad and narrow motifs that typify tropomyosin's twisting superhelical coiled-coil to the wide and tapering tropomyosin densities seen in surface views of F-actin-tropomyosin reconstructions. The functional implications of the F-actin-tropomyosin models determined in this work are discussed. rights reserved.
dc.language.isoen_US
dc.relation<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=21320445&dopt=Abstract">Link to Article in PubMed</a>
dc.relation.urlhttp://dx.doi.org/10.1016/j.bpj.2010.12.3697
dc.subjectActins
dc.subjectAmino Acids
dc.subjectAnimals
dc.subject*Computer Simulation
dc.subjectImage Processing, Computer-Assisted
dc.subjectImaging, Three-Dimensional
dc.subjectMicroscopy, Electron
dc.subjectModels, Molecular
dc.subjectProtein Binding
dc.subjectRabbits
dc.subjectReproducibility of Results
dc.subjectStatic Electricity
dc.subjectTropomyosin
dc.subjectCell Biology
dc.titleTropomyosin position on F-actin revealed by EM reconstruction and computational chemistry
dc.typeJournal Article
dc.source.journaltitleBiophysical journal
dc.source.volume100
dc.source.issue4
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/cellbiology_pp/105
dc.identifier.contextkey2122917
html.description.abstract<p>Electron microscopy and fiber diffraction studies of reconstituted F-actin-tropomyosin filaments reveal the azimuthal position of end-to-end linked tropomyosin molecules on the surface of actin. However, the longitudinal z-position of tropomyosin along F-actin is still uncertain. Without this information, atomic models of F-actin-tropomyosin filaments, free of constraints imposed by troponin or other actin-binding proteins, cannot be formulated, and thus optimal interfacial contacts between actin and tropomyosin remain unknown. Here, a computational search assessing electrostatic interactions for multiple azimuthal locations, z-positions, and pseudo-rotations of tropomyosin on F-actin was performed. The information gleaned was used to localize tropomyosin on F-actin, yielding an atomic model characterized by protein-protein contacts that primarily involve clusters of basic amino acids on actin subdomains 1 and 3 juxtaposed against acidic residues on the successive quasi-repeating units of tropomyosin. A virtually identical model generated by docking F-actin and tropomyosin atomic structures into electron microscopy reconstructions of F-actin-tropomyosin validated the above solution. Here, the z-position of tropomyosin alongside F-actin was defined by matching the seven broad and narrow motifs that typify tropomyosin's twisting superhelical coiled-coil to the wide and tapering tropomyosin densities seen in surface views of F-actin-tropomyosin reconstructions. The functional implications of the F-actin-tropomyosin models determined in this work are discussed. rights reserved.</p>
dc.identifier.submissionpathcellbiology_pp/105
dc.contributor.departmentDepartment of Cell Biology
dc.source.pages1005-13


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