title: Structure-function studies of the magnetite-biomineralizing magnetosome-associated protein MamC.
abstract: Magnetotactic bacteria are Gram-negative bacteria that navigate along geomagnetic fields using the magnetosome, an organelle that consists of a membrane-enveloped magnetic nanoparticle. Magnetite formation and its properties are controlled by a specific set of proteins. MamC is a small magnetosome-membrane protein that is known to be active in iron biomineralization but its mechanism has yet to be clarified. Here, we studied the relationship between the MamC magnetite-interaction loop (MIL) structure and its magnetite interaction using an inert biomineralization protein-MamC chimera. Our determined structure shows an alpha-helical fold for MamC-MIL with highly charged surfaces. Additionally, the MamC-MIL induces the formation of larger magnetite crystals compared to protein-free and inert biomineralization protein control experiments. We suggest that the connection between the MamC-MIL structure and the protein's charged surfaces is crucial for magnetite binding and thus for the size control of the magnetite nanoparticles.
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Hila
authors.initials: H
authors.lastname: Nudelman
authors.affiliation: Universidad de Granada, Departamento de Microbiologia, Campus de Fuentenueva, 18071 Granada, Spain; Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Valverde-Tercedor
authors.affiliation: Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Sofiya
authors.initials: S
authors.lastname: Kolusheva
authors.affiliation: Universidad de Granada, Departamento de Microbiologia, Campus de Fuentenueva, 18071 Granada, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Perez Gonzalez
authors.affiliation: Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Marc
authors.initials: M
authors.lastname: Widdrat
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Noam
authors.initials: N
authors.lastname: Grimberg
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Hilla
authors.initials: H
authors.lastname: Levi
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Or
authors.initials: O
authors.lastname: Nelkenbaum
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Geula
authors.initials: G
authors.lastname: Davidov
authors.affiliation: Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Damien
authors.initials: D
authors.lastname: Faivre
authors.affiliation: Universidad de Granada, Departamento de Microbiologia, Campus de Fuentenueva, 18071 Granada, Spain. Electronic address: cjl@ugr.es.
authors.forename: Concepcion
authors.initials: C
authors.lastname: Jimenez-Lopez
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel. Electronic address: zarivach@bgu.ac.il.
authors.forename: Raz
authors.initials: R
authors.lastname: Zarivach
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000737:chemistry* / Q000378:metabolism; D055944:Magnetosomes / Q000737:chemistry* / Q000502:physiology; D042201:Magnetospirillum; D053758:Nanoparticles / Q000737:chemistry; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D052203:Ferrosoferric Oxide
keywords: Biomineralization; Magnetotactic bacteria; MamC; Protein structure; Structure–activity relationships