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The magnetosome membrane protein, MmsF, is a major regulator of magnetite biomineralization in Magnetospirillum magneticum AMB‐1
Author(s) -
Murat Dorothée,
Falahati Veesta,
Bertinetti Luca,
Csencsits Roseann,
Körnig André,
Downing Kenneth,
Faivre Damien,
Komeili Arash
Publication year - 2012
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2012.08132.x
Subject(s) - magnetosome , magnetotactic bacteria , biomineralization , greigite , biology , magnetite , organelle , gene , microbiology and biotechnology , genetics , paleontology
Summary Magnetotactic bacteria (MTB) use magnetosomes, membrane‐bound crystals of magnetite or greigite, for navigation along geomagnetic fields. In Magnetospirillum magneticum sp. AMB‐1, and other MTB, a magnetosome gene island (MAI) is essential for every step of magnetosome formation. An 8‐gene region of the MAI encodes several factors implicated in control of crystal size and morphology in previous genetic and proteomic studies. We show that these factors play a minor role in magnetite biomineralization in vivo . In contrast, MmsF, a previously uncharacterized magnetosome membrane protein encoded within the same region plays a dominant role in defining crystal size and morphology and is sufficient for restoring magnetite synthesis in the absence of the other major biomineralization candidates. In addition, we show that the 18 genes of the mamAB gene cluster of the MAI are sufficient for the formation of an immature magnetosome organelle. Addition of MmsF to these 18 genes leads to a significant enhancement of magnetite biomineralization and an increase in the cellular magnetic response. These results define a new biomineralization protein and lay down the foundation for the design of autonomous gene cassettes for the transfer of the magnetic phenotype in other bacteria.