Structural highlights
Function
CSS4A_HALNC Probably forms vertices in the carboxysome, a polyhedral inclusion where RuBisCO (ribulose bisphosphate carboxylase, cbbL-cbbS) is sequestered. Has been modeled to induce curvature upon insertion into an otherwise flat hexagonal layer of major carboxysome subunits (Probable). A minor shell protein, only 12 pentamers of CsoS4A/CsoS4B are calculated to be present in each carboxysome. The 2 CsoS4 proteins contribute to the impermeability of the carboxysome to CO(2) (PubMed:19844578).[1] [2] Unlike beta-carboxysomes, alpha-carboxysomes (Cb) can form without cargo protein. CsoS2 is essential for Cb formation and is also capable of targeting foreign proteins to the Cb. The Cb shell assembles with the aid of CsoS2; CsoS1A, CsoS1B and CsoS1C form the majority of the shell while CsoS4A and CsoS4B form vertices. CsoS1D forms pseudohexamers that probably control metabolite flux into and out of the shell.[3]
References
- ↑ Cai F, Menon BB, Cannon GC, Curry KJ, Shively JM, Heinhorst S. The pentameric vertex proteins are necessary for the icosahedral carboxysome shell to function as a CO2 leakage barrier. PLoS One. 2009 Oct 21;4(10):e7521. PMID:19844578 doi:10.1371/journal.pone.0007521
- ↑ Tanaka S, Kerfeld CA, Sawaya MR, Cai F, Heinhorst S, Cannon GC, Yeates TO. Atomic-level models of the bacterial carboxysome shell. Science. 2008 Feb 22;319(5866):1083-6. PMID:18292340 doi:http://dx.doi.org/319/5866/1083
- ↑ Li T, Jiang Q, Huang J, Aitchison CM, Huang F, Yang M, Dykes GF, He HL, Wang Q, Sprick RS, Cooper AI, Liu LN. Reprogramming bacterial protein organelles as a nanoreactor for hydrogen production. Nat Commun. 2020 Oct 28;11(1):5448. doi: 10.1038/s41467-020-19280-0. PMID:33116131 doi:http://dx.doi.org/10.1038/s41467-020-19280-0
