Grant: Discovery Grants Program - Individual

Most cells organize themselves with multiple internal compartments, called organelles, where a range of specialized processes can occur in isolation from the rest of the cell. In some cases organelles protect delicate processes from interference by other cellular factors, and in others cases organelles protect the cell from potentially harmful byproducts. Understanding the processes of cellular compartmentalization is fundamentally important to understanding how cells function. A unique group of magnetotactic bacteria create multiple internal compartments which serves as an enclosed space for controlled formation of a single magnetic nanocrystal. These organelles, called magnetosomes, are positioned in a line running the length of the bacterium, where they act as a compass needle to align the cell in the earth's magnetic field. The magnetic response appears to aid in the search for optimal growth conditions. Because of its small size and limited number of constituent components the magnetosome an ideal model system for deciphering basic principles of organelle formation that hold true in all cells. In addition to what they can teach us about cell biology, magnetosomes may also have practical applications in bio- and nanotechnology. If we can develop strategies to genetically manipulate magnetosomes, we may be able to co-opt them as compartments for biosynthesis of novel compounds, or to synthesize nearly perfect mangetic nanocrystals with novel properties for fabricating nanomachines. Achieving these goals will require a complete understanding of the molecular machinery that drives the magnetosome assembly process. In this proposal, I describe my plans to examine the structures of whole magnetosomes their individual components at atomic scale resolution. Seeing the details of how the magnetosome is built will teach us about the molecular processes that underlie its assembly, and how the synthesis of nanocrystals is controlled. This work will provide us with new insight into fundamental aspects of cell biology, and may have important practical implications for technological advances.