Crystallizing the function of the magnetosome membrane mineralization protein Mms6
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Updated: Oct 22, 2026
Crystallizing Membrane Proteins for Structure Determination using Lipidic Mesophases
Published on: November 21, 2010
Sarah S Staniland1, Andrea E Rawlings2
1Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K. s.s.staniland@sheffield.ac.uk.
Abstract:
The literature on the magnetosome membrane (MM) protein, magnetosome membrane specific6 (Mms6), is reviewed. Mms6 is native to magnetotactic bacteria (MTB). These bacteria take up iron from solution and biomineralize magnetite nanoparticles within organelles called magnetosomes. Mms6 is a small protein embedded on the interior of the MM and was discovered tightly associated with the formed mineral. It has been the subject of intensive research as it is seen to control the formation of particles both in vivo and in vitro Here, we compile, review and discuss the research detailing Mms6's activity within the cell and in a range of chemical in vitro methods where Mms6 has a marked effect on the composition, size and distribution of synthetic particles, with approximately 21 nm in size for solution precipitations and approximately 90 nm for those formed on surfaces. Furthermore, we review and discuss recent work detailing the structure and function of Mms6. From the evidence, we propose a mechanism for its function as a specific magnetite nucleation protein and summaries the key features for this action: namely, self-assembly to display a charged surface for specific iron binding, with the curvature of the surfaces determining the particle size. We suggest these may aid design of biomimetic additives for future green nanoparticle production.
Insights
Magnetosome membrane specific6 (Mms6) protein controls magnetite nanoparticle formation in magnetotactic bacteria. Research suggests Mms6 self-assembles to bind iron, influencing particle size and aiding green nanoparticle production.
Area of Science:
- Biomineralization
- Nanoparticle Synthesis
- Structural Biology
Background:
- Magnetotactic bacteria (MTB) biomineralize magnetite nanoparticles within magnetosomes.
- Magnetosome membrane (MM) protein Mms6 is crucial for controlling magnetite formation.
- Mms6 is found associated with mineral crystals within the MM.
Purpose of the Study:
- To review and discuss Mms6's function in controlling magnetite nanoparticle formation in vitro and in vivo.
- To elucidate the structure and mechanism of Mms6's action.
- To explore Mms6's potential in biomimetic nanoparticle production.
Main Methods:
- Literature review of Mms6 research.
- Analysis of Mms6's effects on synthetic particle formation in various chemical conditions.
- Examination of Mms6 structure and self-assembly properties.
Main Results:
- Mms6 influences the composition, size, and distribution of synthetic magnetite nanoparticles.
- Solution precipitation yields ~21 nm particles, while surface-mediated formation yields ~90 nm particles.
- Mms6 self-assembles, exposing a charged surface for iron binding, with surface curvature dictating particle size.
Conclusions:
- Mms6 acts as a specific magnetite nucleation protein.
- The proposed mechanism involves Mms6 self-assembly and iron binding, with surface curvature controlling size.
- Mms6's properties may inform the design of additives for green nanoparticle synthesis.
