Encapsulin nanocompartment

Crystal structure of Thermotoga maritima encapsulin. PDB entry 3dkt

Encapsulin nanocompartments, or encapsulin protein cages, are spherical bacterial organelle-like compartments roughly 25-30 nm in diameter that are involved in various aspects of metabolism, in particular protecting bacteria from oxidative stress. Encapsulin nanocompartments are structurally similar to the HK97 bacteriophage and their function depends on the proteins loaded into the nanocompartment.[1] The sphere is formed from 60 (for a 25 nm sphere) or 180 (for a 30 nm sphere) copies of a single protomer, termed encapsulin. Their structure has been studied in great detail using X-ray crystallography[2] and cryo-electron microscopy.[3]

A number of different types of proteins have been identified as being loaded into encapsulin nanocompartments. Peroxidases or proteins similar to ferritins are the two most common types of cargo proteins.[4] While most encapsulin nanocompartments contain only one type of cargo protein, in some species two or three types of cargo proteins are loaded.[2][3][4]

Encapsulins purified from Rhodococcus jostii can be assembled and disassembled with changes in pH. In the assembled state, the compartment enhances the activity of its cargo, a peroxidase enzyme.[5]

  1. ^ Nichols, Robert J.; Cassidy-Amstutz, Caleb; Chaijarasphong, Thawatchai; Savage, David F. (October 2017). "Encapsulins: molecular biology of the shell". Critical Reviews in Biochemistry and Molecular Biology. 52 (5): 583–594. doi:10.1080/10409238.2017.1337709. ISSN 1549-7798. PMID 28635326. S2CID 205695184.
  2. ^ a b Sutter, M; Boehringer, D; Gutmann, S; Günther, S; Prangishvili, D; Loessner, MJ; Stetter, KO; Weber-Ban, E; Ban, N (September 2008). "Structural basis of enzyme encapsulation into a bacterial nanocompartment". Nature Structural & Molecular Biology. 15 (9): 939–47. doi:10.1038/nsmb.1473. hdl:20.500.11850/150838. PMID 19172747. S2CID 205522743.
  3. ^ a b McHugh, CA; Fontana, J; Nemecek, D; Cheng, N; Aksyuk, AA; Heymann, JB; Winkler, DC; Lam, AS; Wall, JS; Steven, AC; Hoiczyk, E (1 September 2014). "A virus capsid-like nanocompartment that stores iron and protects bacteria from oxidative stress". The EMBO Journal. 33 (17): 1896–911. doi:10.15252/embj.201488566. PMC 4195785. PMID 25024436.
  4. ^ a b Giessen, Tobias W.; Silver, Pamela A. (2017-03-06). "Widespread distribution of encapsulin nanocompartments reveals functional diversity". Nature Microbiology. 2 (6): 17029. doi:10.1038/nmicrobiol.2017.29. ISSN 2058-5276. PMID 28263314. S2CID 5549808.
  5. ^ Rahmanpour, Rahman; Bugg, Timothy D. H. (2013-05-01). "Assembly in vitro of Rhodococcus jostii RHA1 encapsulin and peroxidase DypB to form a nanocompartment" (PDF). The FEBS Journal. 280 (9): 2097–2104. doi:10.1111/febs.12234. ISSN 1742-4658. PMID 23560779.