title: Co-ordinated functions of Mms proteins define the surface structure of cubo-octahedral magnetite crystals in magnetotactic bacteria.
abstract: Magnetotactic bacteria synthesize magnetosomes comprised of membrane-enveloped single crystalline magnetite (Fe3 O4 ). The size and morphology of the nano-sized magnetite crystals (< 100 nm) are highly regulated and bacterial species dependent. However, the control mechanisms of magnetite crystal morphology remain largely unknown. The group of proteins, called Mms (Mms5, Mms6, Mms7, and Mms13), was previously isolated from the surface of cubo-octahedral magnetite crystals in Magnetospirillum magneticum strain AMB-1. Analysis of an mms6 gene deletion mutant suggested that the Mms6 protein plays a major role in the regulation of magnetite crystal size and morphology. In this study, we constructed various mms gene deletion mutants and characterized the magnetite crystals formed by the mutant strains. Comparative analysis showed that all mms genes were involved in the promotion of crystal growth in different manners. The phenotypic characterization of magnetites also suggested that these proteins are involved in controlling the geometries of the crystal surface structures. Thus, the co-ordinated functions of Mms proteins regulate the morphology of the cubo-octahedral magnetite crystals in magnetotactic bacteria.
authors: Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan.
authors: Atsushi
authors: A
authors: Arakaki
authors: Ayana
authors: A
authors: Yamagishi
authors: Ayumi
authors: A
authors: Fukuyo
authors: Masayoshi
authors: M
authors: Tanaka
authors: Tadashi
authors: T
authors: Matsunaga
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D003460:Crystallization; D052203:Ferrosoferric Oxide / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D017353:Gene Deletion; D006090:Gram-Negative Bacteria / Q000235:genetics; D055944:Magnetosomes / Q000648:ultrastructure; D042201:Magnetospirillum / Q000737:chemistry* / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009154:Mutation
chemical_list: D001426:Bacterial Proteins; D052203:Ferrosoferric Oxide