ABSTRACT
Compartmentalization is a common theme in biology. Barriers enforce chemical and physical separations dening self from the surrounding environment. In higher organisms, compartmentalization is hierarchical extending from the outer barriers that dene the organism down to individual cells and subcellular structures such as organelles. Each level of compartmentalization enables essential functions of the organism. Cellular structural compartmentalization and organization of enzymes and metabolic pathways provide a control for the relative ux and efciency of metabolism as well as protection and sequestration of enzymes and metabolites [1-3]. In addition, biological barriers enable macromolecular densities on the order of 300 mg/mL within the cell, which is vastly different from the conditions used for
typical enzyme characterization [4,5]. Structural compartmentalization is a largely untapped resource for enzymatic and metabolic engineering as well as a key point of study for understanding metabolism at the cellular level. One factor inhibiting the study and utility of eukaryotic metabolic structural organization is the complexity and heterogeneity of these systems. Simpler candidates are needed to begin digging into enzyme compartmentalization as a tool and natural phenomenon.
