title: TubZ filament assembly dynamics requires the flexible C-terminal tail.
abstract: Cytomotive filaments are essential for the spatial organization in cells, showing a dynamic behavior based on nucleotide hydrolysis. TubZ is a tubulin-like protein that functions in extrachromosomal DNA movement within bacteria. TubZ filaments grow in a helical fashion following treadmilling or dynamic instability, although the underlying mechanism is unclear. We have unraveled the molecular basis for filament assembly and dynamics combining electron and atomic force microscopy and biochemical analyses. Our findings suggest that GTP caps retain the filament helical structure and hydrolysis triggers filament stiffening upon disassembly. We show that the TubZ C-terminal tail is an unstructured domain that fulfills multiple functions contributing to the filament helical arrangement, the polymer remodeling into tubulin-like rings and the full disassembly process. This C-terminal tail displays the binding site for partner proteins and we report how it modulates the interaction of the regulator protein TubY.
authors.affiliation: CSIC - Centro Nacional de Biotecnología, Department of Macromolecular Structures, Cantoblanco, Madrid, 28049, Spain.|Department of Medicine, Section of Virology, Imperial College, Du Cane Road, London, W120NN, UK.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Fuentes-Pérez
authors.affiliation: CSIC - Centro de Investigaciones Biológicas, Department of Chemical and Physical Biology, Madrid, 28040, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Núñez-Ramírez
authors.affiliation: CSIC - Centro Nacional de Biotecnología, Department of Macromolecular Structures, Cantoblanco, Madrid, 28049, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Martín-González
authors.affiliation: CSIC - Centro de Investigaciones Biológicas, Department of Chemical and Physical Biology, Madrid, 28040, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Juan-Rodríguez
authors.affiliation: CSIC - Centro de Investigaciones Biológicas, Department of Chemical and Physical Biology, Madrid, 28040, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Llorca
authors.affiliation: CSIC - Centro Nacional de Biotecnología, Department of Macromolecular Structures, Cantoblanco, Madrid, 28049, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Moreno-Herrero
authors.affiliation: CSIC - Centro de Investigaciones Biológicas, Department of Chemical and Physical Biology, Madrid, 28040, Spain.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Oliva
mesh_terms: D001413:Bacillus thuringiensis / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D018625:Microscopy, Atomic Force; D008854:Microscopy, Electron; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D006160:Guanosine Triphosphate