Difference between revisions of "Part:BBa K4229042"

Revision as of 17:58, 11 October 2022

H and T1 protein from the BMC building the minimal "wiffleball"

Bacterial microcompartments (BMCs) are self-organising organelles with a selectively permeable protein shell. All BMCs consist of three conserved families of proteins: BMC-H (forming hexamers), BMC-T (pseudohexamers) both with pores of different sizes in the middle and BMC-P (pentamers) [1][2]. Small molecules can enter the lumen of BMCs via the pores found within the BMC-H shell proteins (which vary in size from 4 - 7Å in diameter) or the larger pores (~12 - 14 Å in diameter) formed by BMC-T trimers which can have an open or closed confirmation [3][4]. For our project, we used the recently published synthetic BMCs from Kirst et al [32], which based on the shell system from the myxobacterium Haliangium ochraceum (HO-shell) (Figure 3A). The HO-shell is able to assemble without containing any cargo molecule inside [32][35] and is built by the shell proteins BMC-H, BMC-P and three BMC-T proteins (single-layer T1, and double-layer T2 and T3). The synthetic BMC shell, designed by the Kerfeld lab can form without the presence of the BMC-P proteins (Figure 3B) [29][36]. Without the pentamers, there are pores left that allow molecules to diffuse in/out of the lumen of the BMC. This form of the synthetic BMC is called full wiffleball. An even more simplified shell (minimal wiffleball) was designed to consist only two shell proteins, BMC-H and BMC-T1 (Figure 3C).

Synthetic BMCs serve as autonomous metabolic modules, which are decoupled from the regulatory mechanisms of the cell and are only connected to the metabolism of the cell via the engineered protein envelope [32]

[1] C. A. Kerfeld, C. Aussignargues, J. Zarzycki, F. Cai, and M. Sutter, “Bacterial microcompartments,” Nat. Rev. Microbiol., vol. 16, no. 5, pp. 277–290, 2018, doi: 10.1038/nrmicro.2018.10.

[2] H. Kirst, B. H. Ferlez, S. N. Lindner, C. A. R. Cotton, A. Bar-Even, and C. A. Kerfeld, “Toward a glycyl radical enzyme containing synthetic bacterial microcompartment to produce pyruvate from formate and acetate,” Proc. Natl. Acad. Sci. U. S. A., vol. 119, no. 8, pp. 1–10, 2022, doi: 10.1073/pnas.2116871119. Sequence and Features