Visualization of Iron-Binding Micelles in Acidic Recombinant Biomineralization Protein, MamC

Biological macromolecules are utilized in low-temperature synthetic methods to exert precise control over nanoparticle nucleation and placement. They enable low-temperature formation of a variety of functional nanostructured materials with properties often not achieved via conventional synthetic techniques. Here we report on the in situ visualization of a novel acidic bacterial recombinant protein, MamC, commonly present in the magnetosome membrane of several magnetotactic bacteria, including Magnetococcus marinus, strain MC-1. Our findings provide an insight into the self-assembly of MamC and point to formation of the extended protein surface, which is assumed to play an important role in the formation of biotemplated inorganic nanoparticles. The self-organization of MamC is compared to the behavior of another acidic recombinant iron-binding protein, Mms6.This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The research was performed at the Ames Laboratory, which is operated for the U.S. Department of Energy by Iowa State University under Contract no. DE-AC02-07CH11358. MamC cloning and purification were done at the University of Granada, Spain. Concepción Jiménez López acknowledges the support from the Spanish Government through Grant CGL2010-18274 and the program Salvador de Madariaga