Bacterial microcompartment
A bacterial microcompartment is a structure inside bacteria. They are made of a protein shell which surrounds and encloses various enzymes.[1] They are similar to eukaryotic cell organelles, but do not have plasma membranes. They do not contain lipids.[2]
These compartments are typically about 100-200 nanometres across and made of interlocking proteins.[3]
Protein-enclosed compartments are also found in eukaryotes, such as enzyme encapsulation.[4]
Bacterial Microcompartment Media
The first structure of a bacterial microcompartment shell, determined by X-ray crystallography and cryo-electron microscopy contains representatives of each of the shell protein types: BMC-P, BMC-H and BMC-T, in both its trimer (upper right) and dimer of trimer (lower right), forms.
Generalized function schematic for experimentally characterized BMCs. (A) Carboxysome. (B) Metabolosome. Reactions in gray are peripheral reactions to the core BMC chemistry. BMC shell protein oligomers are depicted on the left: blue, BMC-H; cyan, BMC-T; yellow, BMC-P. 3-PGA, 3-phosphoglycerate, and RuBP, ribulose 1,5-bisphosphate.
Electron micrographs showing alpha-carboxysomes from the chemoautotrophic bacterium Halothiobacillus neapolitanus: (A) arranged within the cell, and (B) intact upon isolation. Scale bars indicate 100 nm.
Electron micrograph of Synechococcus elongatus PCC 7942 cell showing the carboxysomes as polyhedral dark structures. Scale bar indicates 500 nm.
References
- ↑ Bobik T.A.. Bacterial microcompartments. Microbe 2 (2007)Am Soc Microbiol. p. 25–31. Retrieved 2011-01-06.
- ↑ Sutter M, Boehringer D, Gutmann S. Structural basis of enzyme encapsulation into a bacterial nanocompartment. Nat. Struct. Mol. Biol. 15 (9) (August 2008). p. 939–947. doi:10.1038/nsmb.1473.
- ↑ Yeates TO, Kerfeld CA, Heinhorst S, Cannon GC, Shively JM. Protein-based organelles in bacteria: carboxysomes and related microcompartments. Nat. Rev. Microbiol. 6 (9) (August 2008). p. 681–691. doi:10.1038/nrmicro1913.
- ↑ Kedersha NL, Miquel MC, Bittner D, Rome LH. Vaults. II. Ribonucleoprotein structures are highly conserved among higher and lower eukaryotes.. J Cell Biol 110 (4) (1990). p. 895–901. doi:10.1083/jcb.110.4.895.