Engineered Shell Proteins to Enable Electron Transfer Across the Shell of a Bacterial Microcompartment


Bacterial microcompartments (BMCs) are organelles used by various bacteria to encapsulate metabolic pathways into a proteinaceous shell. Because of their attributes (self-assembling modules, optimization of the reactions in their lumen.) they have potential as catalytic bioreactors that can be customized to support new metabolic functions. The introduction in the shell of an electron transfer functionality would allow the encapsulation of oxidoreduction pathways of biotechnological interest, therefore expanding the functional repertoire of these BMCs. It has been demonstrated that synthetic BMC shells can be generated (Lassila et al., J Mol. Biol, 2014 426(11)) and to this end enables development of this technology.

BMC’s are currently known to carry out aldehyde oxidation metabolisms on small molecules including propandiol, ethanolamine, and amino-2-propanols. Intermediates generated in the breakdown of these molecules are known to be damaging to the cell. The core enzymes of these BMCs are aldehyde dehydrogenase, alcohol dehydrogenase, and phospotransacylase.


This technology is the bacterial microcompartment shell protein BMC-T1 from Haliangium ochraceum engineered to contain [4Fe-4S] clusters through specific point mutations. These clusters allow for the continued transfer of electrons (oxidation-reduction cycles) from one side of the bacterial microcompartment to the other. This technology provides three varieties of the modified BMC-T1 protein through 3 specific point mutations in the interprotein pore, which enables several redox potentials to cater to various needs. This technology enables bacterial microcompartments to become novel nanobio catalytic sites in vivo or in vitro.


  • Contained redox reactions
  • Platform for intracellular biotransformations 
  • Faster, more efficient biotransformations 


  • Bionanoreactors
  • Biofuel production (hydrogen)
  • Bio circuits 


US 16/654,894 pending



For more information about this technology, contact Julia Miller at or (517) 884-0721.

Patent Information:

For Information, Contact:

Julia Miller
AgBio Technology Manager
Michigan State University