5ho3

MamBMamB

Structural highlights 5ho3 is a 2 chain structure with sequence from Magnetospira sp. QH-2. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.15Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MAMB_MAGSQ Plays a dual, essential role in magnetosome formation; required for magnetosome vesicle formation as well as biomineralization (By similarity). Probably binds and transports iron (Probable). Requires heterodimerization with MamM for stability (By similarity).[UniProtKB:V6F510] Publication Abstract from PubMed Magnetospirillum gryphiswaldense MSR-1 synthesizes membrane-enclosed magnetite (Fe3 O4 ) nanoparticles, magnetosomes, for magnetotaxis. Formation of these organelles involves a complex process comprising key steps which are governed by specific magnetosome-associated proteins. MamB, a cation diffusion facilitator (CDF) family member has been implicated in magnetosome-directed iron transport. However, deletion mutagenesis studies revealed that MamB is essential for the formation of magnetosome membrane vesicles, but its precise role remains elusive. In this study, we employed a multi-disciplinary approach to define the role of MamB during magnetosome formation. Using site-directed mutagenesis complemented by structural analyses, fluorescence microscopy and cryo-electron tomography, we show that MamB is most likely an active magnetosome-directed transporter serving two distinct, yet essential functions. First, MamB initiates magnetosome vesicle formation in a transport-independent process, probably by serving as a landmark protein. Second, MamB transport activity is required for magnetite nucleation. Furthermore, by determining the crystal structure of the MamB cytosolic C-terminal domain, we also provide mechanistic insight into transport regulation. Additionally, we present evidence that magnetosome vesicle growth and chain formation are independent of magnetite nucleation and magnetic interactions respectively. Together, our data provide novel insight into the role of the key bifunctional magnetosome protein MamB, and the early steps of magnetosome formation. The dual role of MamB in magnetosome membrane assembly and magnetite biomineralization.,Uebe R, Keren-Khadmy N, Zeytuni N, Katzmann E, Navon Y, Davidov G, Bitton R, Plitzko JM, Schuler D, Zarivach R Mol Microbiol. 2018 Feb;107(4):542-557. doi: 10.1111/mmi.13899. Epub 2018 Jan 9. PMID:29243866 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 5ho3, resolution 2.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image