title: Monomeric and dimeric conformation of the vinculin tail five-helix bundle in solution studied by EPR spectroscopy.
abstract: The cytoskeletal adaptor protein vinculin plays an important role in the control of cell adhesion and migration, linking the actin cytoskeleton to adhesion receptor complexes in cell adhesion sites. The conformation of the vinculin tail dimer, which is crucial for protein function, was analyzed using site-directed spin labeling in electron paramagnetic resonance spectroscopy. Interspin distances for a set of six singly and four doubly spin-labeled mutants of the tail domain of vinculin were determined and used as constraints for modeling of the vinculin tail dimer. A comparison of the results obtained by molecular dynamic simulations and a rotamer library approach reveals that the crystal structure of the vinculin tail monomer is essentially preserved in aqueous solution. The orientation of monomers within the dimer observed previously by x-ray crystallography agrees with the solution electron paramagnetic resonance data. Furthermore, the distance between positions 1033 is shown to increase by >3 nm upon interaction of the vinculin tail domain with F-actin.
authors.affiliation: Department of Physics, University of Osnabrück, Osnabrück, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Abé
authors.forename: Franziska
authors.initials: F
authors.lastname: Dietrich
authors.forename: Prasad
authors.initials: P
authors.lastname: Gajula
authors.forename: Monique
authors.initials: M
authors.lastname: Benz
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Vogel
authors.forename: Maurice
authors.initials: M
authors.lastname: van Gastel
authors.forename: Susanne
authors.initials: S
authors.lastname: Illenberger
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Ziegler
authors.forename: Heinz-Jürgen
authors.initials: HJ
authors.lastname: Steinhoff
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D056004:Molecular Dynamics Simulation; D009068:Movement; D016296:Mutagenesis; D009154:Mutation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D012996:Solutions; D013113:Spin Labels; D016596:Vinculin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D012996:Solutions; D013113:Spin Labels; D016596:Vinculin