A Large Gene Cluster Encoding Several Magnetosome Proteins Is Conserved in Different Species of Magnetotactic Bacteria

Grünberg, Karen; Wawer, Cathrin; Tebo, Bradley M.; Schüler, Dirk

doi:10.1128/aem.67.10.4573-4582.2001

Cited by 276 publications

(296 citation statements)

References 48 publications

Supporting

Mentioning

280

Contrasting

Unclassified

Order By: Relevance

“…Of these genes encoding potential structural proteins, one mreB gene is highly conserved among the genomes of magnetic coccus MC-1, M. magnetotacticum, and M. gryphiswaldense. The highly conserved actin homologue is also part of a larger group (the magnetosome island) of conserved genes containing 18 proteins known to be located on the magnetosome [47,51]. The conserved MreB-like protein, named MamK in M. gryphiswaldense, is not bound to the magnetosome membrane in extracted magnetosomes [47].…”

Section: Discussionmentioning

confidence: 99%

Experimental observation of magnetosome chain collapse in magnetotactic bacteria: Sedimentological, paleomagnetic, and evolutionary implications

Kobayashi

Kirschvink

Nash

et al. 2006

Earth and Planetary Science Letters

101

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Experimental observation of magnetosome chain collapse in magnetotactic bacteria: Sedimentological, paleomagnetic, and evolutionary implications

Kobayashi

Kirschvink

Nash

et al. 2006

Earth and Planetary Science Letters

101

View full text Add to dashboard Cite

“…From the obtained sequences, a spot with an approximate molecular mass of 13 kDa (pI 7.2) was determined as a homolog of MamC in M. gryphiswaldense (12). The molecular size visualized by Tricine/SDS matched the reported size of MamC.…”

Section: Isolation Of Proteins Tightlymentioning

confidence: 92%

“…From motif analysis, this is considered to function as a receptor interacting with associated cytoplasmic proteins (11). Recently, Grü nberg et al (12) cloned and sequenced four genes that were assigned to two different genomic regions coding for BMP membrane-specific proteins in Magnetospirillum gryphiswaldense MSR-1.…”

mentioning

confidence: 99%

A Novel Protein Tightly Bound to Bacterial Magnetic Particles in Magnetospirillum magneticum Strain AMB-1

Arakaki

Webb

Matsunaga

2003

Journal of Biological Chemistry

355

539

View full text Add to dashboard Cite

Magnetic bacteria synthesize magnetite crystals with species-dependent morphologies. The molecular mechanisms that control nano-sized magnetite crystal formation and the generation of diverse morphologies are not well understood. From the analysis of magnetite crystalassociated proteins, several low molecular mass proteins tightly bound to bacterial magnetite were obtained from Magnetospirillum magneticum strain AMB-1. These proteins showed common features in their amino acid sequences, which contain hydrophobic Nterminal and hydrophilic C-terminal regions. The Cterminal regions in Mms5, Mms6, Mms7, and Mms13 contain dense carboxyl and hydroxyl groups that bind iron ions. Nano-sized magnetic particles similar to those in magnetic bacteria were prepared by chemical synthesis of magnetite in the presence of the acidic protein Mms6. These proteins may be directly involved in biological magnetite crystal formation in magnetic bacteria.Magnetic bacteria synthesize nano-sized magnetic particles of an iron oxide, magnetite (Fe 3 O 4 ); an iron sulfide, greigite (Fe 3 S 4 ); or a combination of greigite and iron pyrite (Fe 2 S) (1-3). These particles are individually covered with a stable lipid bilayer membrane that mainly consists of lipid and protein (4). The mineral size, type, and morphology of bacterial magnetic particles (BMPs) 1 are highly controlled within bacterial species or strains (5). The species-specific control of BMP formation has focused attention on the possible roles of the surrounding membrane structures.The molecular mechanism of BMP synthesis is a multistep process, including vesicle formation, iron transport, and magnetite crystallization (5, 6). Recent molecular studies have postulated the steps of BMP synthesis (7-9). Several proteins located on or in the BMP membrane have been isolated and analyzed in Magnetospirillum magneticum strain AMB-1. The first event of BMP synthesis is the formation of vesicles. Invagination of the cytoplasmic membrane is primed by a BMP membrane-specific GTPase (Mms16) to form the intracellular vesicle (7). MpsA, a homolog of an acetyltransferase containing a CoA-binding motif, is also considered to be involved in this process (8). The second process in BMP synthesis is iron transport into the BMP vesicles. It appears that ferric iron is reduced on the cell surface, taken into the cytoplasm, transported into the BMP vesicle, and finally oxidized to produce magnetite. The magA gene was isolated through transposon mutagenesis in strain AMB-1 (9). This gene encodes an integral membrane protein that is involved in the transport of iron into the BMP vesicles. The last process is crystallization of magnetite within the vesicle, but the process remains unclear.Other proteins associated with the BMP membrane have been partially characterized in magnetic bacteria to date. To understand the molecular mechanism of magnetite crystallization in M. magneticum AMB-1, several proteins tightly bound to the bacterial magnetite crystals were isolated and characterized. A new class of mi...

show abstract

“…One of these is a 24 kDa protein designated as Mms24, which was observed in other Magnetospirillum spp. and corresponds to Mam22 in M. magnetotacticum MS-1 (Okuda et al 1996) and MamA in M. gryphiswaldense MSR-1 (Grünberg et al 2001). A mutant strain harbouring the defected gene encoding this protein showed lesser BacMP formation in comparison with its wild-type counterpart, suggesting that the protein may be required for the activation of BacMP vesicles (Komeili et al 2004).…”

Section: Protein Analyses Of the Bacmp Membranementioning

confidence: 96%

Formation of magnetite by bacteria and its application

Arakaki

Nakazawa

Nemoto

et al. 2008

J. R. Soc. Interface.

220

176

View full text Add to dashboard Cite

Magnetic particles offer high technological potential since they can be conveniently collected with an external magnetic field. Magnetotactic bacteria synthesize bacterial magnetic particles (BacMPs) with well-controlled size and morphology. BacMPs are individually covered with thin organic membrane, which confers high and even dispersion in aqueous solutions compared with artificial magnetites, making them ideal biotechnological materials. Recent molecular studies including genome sequence, mutagenesis, gene expression and proteome analyses indicated a number of genes and proteins which play important roles for BacMP biomineralization. Some of the genes and proteins identified from these studies have allowed us to express functional proteins efficiently onto BacMPs, through genetic engineering, permitting the preservation of the protein activity, leading to a simple preparation of functional protein-magnetic particle complexes. They were applicable to high-sensitivity immunoassay, drug screening and cell separation. Furthermore, fully automated single nucleotide polymorphism discrimination and DNA recovery systems have been developed to use these functionalized BacMPs. The nano-sized fine magnetic particles offer vast potential in new nano-techniques.

show abstract

A Large Gene Cluster Encoding Several Magnetosome Proteins Is Conserved in Different Species of Magnetotactic Bacteria

Cited by 276 publications

References 48 publications

Experimental observation of magnetosome chain collapse in magnetotactic bacteria: Sedimentological, paleomagnetic, and evolutionary implications

Experimental observation of magnetosome chain collapse in magnetotactic bacteria: Sedimentological, paleomagnetic, and evolutionary implications

A Novel Protein Tightly Bound to Bacterial Magnetic Particles in Magnetospirillum magneticum Strain AMB-1

Formation of magnetite by bacteria and its application

Contact Info

Product

Resources

About