Team:Hong Kong HKU

Bacterial Microcompartments (MCP) are closed polyhedral shells, diameter of 100-150nm, which is made of thin protein sheets, enclosing enzymes and cofactors for various forms of fermentative metabolism. Salmonella enteric enthanolamine ultilization (Eut) MCP is one example. 5 genes (Eut S, M, N, L, K) encodes thousands of copies of shell proteins to form a heterogenous MCP shell and empty recombinant Eut Shell has been successfully expressed in E.coli. In addition, a localization signal (N terminal of EutC19) has been identified and signal fused enzymes/ proteins could be targeted to the cavity of the MCP. Inspired by these studies, we think this Eut MCP can become a versatile tool if we can: (a) Modify its exterior surface to enable surface display (b) Localize special enzyme into the MCP to enable specific metabolism (c) Store useful or harmful molecules into the MCP In this iGEM project, using Eut Microcompartment, we aim to show: (1) MCP shell surface can be used to display specific peptides, without disrupting the MCP structure, to enable cell-specific targeting for drug delivery system, easy purification etc. We will display Flag and His tag as a proof of concept. (2) Localize polyphosphate kinase (ppk1) into the native/ engineered MCP to polymerize inorganic phosphate and accumulate them in MCP, trying to treat phosphate pollution in waste water. We will divide into 2 parallel sub-teams, specifically working on surface decoration and ppk enzyme.