Encapsulins are bacterial organelle-like cages involved in various aspects of metabolism, especially protection from oxidative stress. They can serve as vehicles for a wide range of medical applications. Encapsulin shell proteins are structurally similar to HK97 bacteriophage capsid protein and their function depends on the encapsulated cargos. The Myxococcus xanthus encapsulin system comprises EncA and three cargos: EncB, EncC, and EncD. EncB and EncC are similar to bacterial ferritins that can oxidize Fe to less toxic Fe. We analyzed EncA, EncB, and EncC by cryo-EM and X-ray crystallography. Cryo-EM shows that EncA cages can have T = 3 and T = 1 symmetry and that EncA T = 1 has a unique protomer arrangement. Also, we define EncB and EncC binding sites on EncA. X-ray crystallography of EncB and EncC reveals conformational changes at the ferroxidase center and additional metal binding sites, suggesting a mechanism for Fe oxidation and storage within the encapsulin shell.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8995368 | PMC |
| http://dx.doi.org/10.1016/j.str.2022.01.008 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
encapsulin cargo protein EncD is a flavin-binding protein with ferric reductase activity.
Proc Natl Acad Sci U S A
May 2024
Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD 20892.
Article Synopsis
- Encapsulins are protein compartments in bacteria that help manage metabolism and protect against oxidative stress by storing iron.
- The structure of the protein EncD, part of the encapsulin system, was identified as an α-helical dimer and is unique among flavin-binding proteins due to its lack of a β-sheet.
- EncD acts as a ferric reductase, playing a crucial role in the encapsulin's iron management system, which could have implications for developing treatments for diseases related to oxidative stress.
Condensation and Protection of DNA by the Encapsulin: A Novel Function.
Int J Mol Sci
July 2022
UCIBIO-Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
Encapsulins are protein nanocages capable of harboring smaller proteins (cargo proteins) within their cavity. The function of the encapsulin systems is related to the encapsulated cargo proteins. The encapsulin (EncA) naturally encapsulates ferritin-like proteins EncB and EncC as cargo, resulting in a large iron storage nanocompartment, able to accommodate up to 30,000 iron atoms per shell.
View Article and Find Full Text PDFStructural characterization of the Myxococcus xanthus encapsulin and ferritin-like cargo system gives insight into its iron storage mechanism.
Structure
April 2022
Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
Encapsulins are bacterial organelle-like cages involved in various aspects of metabolism, especially protection from oxidative stress. They can serve as vehicles for a wide range of medical applications. Encapsulin shell proteins are structurally similar to HK97 bacteriophage capsid protein and their function depends on the encapsulated cargos.
View Article and Find Full Text PDFA virus capsid-like nanocompartment that stores iron and protects bacteria from oxidative stress.
EMBO J
September 2014
W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
Living cells compartmentalize materials and enzymatic reactions to increase metabolic efficiency. While eukaryotes use membrane-bound organelles, bacteria and archaea rely primarily on protein-bound nanocompartments. Encapsulins constitute a class of nanocompartments widespread in bacteria and archaea whose functions have hitherto been unclear.
View Article and Find Full Text PDFGenome-based cluster deletion reveals an endocrocin biosynthetic pathway in Aspergillus fumigatus.
Appl Environ Microbiol
June 2012
Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Endocrocin is a simple anthraquinone frequently identified in extracts of numerous fungi. Several biosynthetic schemes for endocrocin synthesis have been hypothesized, but to date, no dedicated secondary metabolite gene cluster that produces this polyketide as its major metabolite has been identified. Here we describe our biosynthetic and regulatory characterization of the endocrocin gene cluster in Aspergillus fumigatus.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!