7s5c
M. xanthus ferritin-like protein EncB
Structural highlights
FunctionENCB_MYXXD Cargo protein of a type 1 encapsulin nanocompartment. May help nucleate Fe atoms in the interior of the encapsulin nanocompartment (Probable). Present in about 36 copies/encapsulin nanocompartment (PubMed:25024436).[1] [2] Publication Abstract from PubMedEncapsulins 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(+2) to less toxic Fe(+3). 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. Structural characterization of the Myxococcusxanthus encapsulin and ferritin-like cargo system gives insight into its iron storage mechanism.,Eren E, Wang B, Winkler DC, Watts NR, Steven AC, Wingfield PT Structure. 2022 Feb 2. pii: S0969-2126(22)00008-9. doi:, 10.1016/j.str.2022.01.008. PMID:35150605[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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