title: A major determinant for gliding motility in Mycoplasma genitalium: the interaction between the terminal organelle proteins MG200 and MG491.
abstract: Several mycoplasmas, such as the emergent human pathogen Mycoplasma genitalium, developed a complex polar structure, known as the terminal organelle (TO), responsible for a new type of cellular motility, which is involved in a variety of cell functions: cell division, adherence to host cells, and virulence. The TO cytoskeleton is organized as a multisubunit dynamic motor, including three main ultrastructures: the terminal button, the electrodense core, and the wheel complex. Here, we describe the interaction between MG200 and MG491, two of the main components of the TO wheel complex that connects the TO with the cell body and the cell membrane. The interaction between MG200 and MG491 has a KD in the 80 nm range, as determined by surface plasmon resonance. The interface between the two partners was confined to the "enriched in aromatic and glycine residues" (EAGR) box of MG200, previously described as a protein-protein interaction domain, and to a 25-residue-long peptide from the C-terminal region of MG491 by surface plasmon resonance and NMR spectroscopy studies. An atomic description of the MG200 EAGR box binding surface was also provided by solution NMR. An M. genitalium mutant lacking the MG491 segment corresponding to the peptide reveals specific alterations in cell motility and cell morphology indicating that the MG200-MG491 interaction plays a key role in the stability and functioning of the TO.
authors.affiliation: From the Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Científic de Barcelona, Baldiri Reixac 10, 08028 Barcelona, Spain.
authors.forename: Luca
authors.initials: L
authors.lastname: Martinelli
authors.affiliation: the Magnetic Resonance Center and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Lalli
authors.affiliation: the Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: García-Morales
authors.affiliation: the Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Ratera
authors.affiliation: the Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Querol
authors.affiliation: the Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Piñol
authors.affiliation: From the Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Científic de Barcelona, Baldiri Reixac 10, 08028 Barcelona, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Fita
authors.affiliation: the Structural Biology Group, European Synchrotron Radiation Facility, CS 40220, 38043 Grenoble, France, and the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4150-180 Porto, Portugal barbara.calisto@esrf.fr.
authors.forename: Bárbara M
authors.initials: BM
authors.lastname: Calisto
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D002465:Cell Movement; D002942:Circular Dichroism; D004926:Escherichia coli / Q000378:metabolism; D005816:Genetic Complementation Test; D009682:Magnetic Resonance Spectroscopy; D020409:Molecular Motor Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D045704:Mycoplasma genitalium / Q000166:cytology*; D015388:Organelles / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D017386:Sequence Homology, Amino Acid; D020349:Surface Plasmon Resonance
chemical_list: D001426:Bacterial Proteins; D020409:Molecular Motor Proteins; D010455:Peptides
keywords: Cell Motility; Nuclear Magnetic Resonance (NMR); Protein Structure; Protein-Protein Interaction; Structural Biology