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-Structure paper
Title | CryoEM reveals oligomeric isomers of a multienzyme complex and assembly mechanics. |
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Journal, issue, pages | J Struct Biol X, Vol. 7, Page 100088, Year 2023 |
Publish date | Apr 8, 2023 |
Authors | Jane K J Lee / Yun-Tao Liu / Jason J Hu / Inna Aphasizheva / Ruslan Aphasizhev / Z Hong Zhou / |
PubMed Abstract | Propionyl-CoA carboxylase (PCC) is a multienzyme complex consisting of up to six α-subunits and six β-subunits. Belonging to a metabolic pathway converging on the citric acid cycle, it is present ...Propionyl-CoA carboxylase (PCC) is a multienzyme complex consisting of up to six α-subunits and six β-subunits. Belonging to a metabolic pathway converging on the citric acid cycle, it is present in most forms of life and irregularities in its assembly lead to serious illness in humans, known as propionic acidemia. Here, we report the cryogenic electron microscopy (cryoEM) structures and assembly of different oligomeric isomers of endogenous PCC from the parasitic protozoan (LtPCC). These structures and their statistical distribution reveal the mechanics of PCC assembly and disassembly at equilibrium. We show that, in solution, endogenous LtPCC β-subunits form stable homohexamers, to which different numbers of α-subunits attach. Sorting LtPCC particles into seven classes (i.e., oligomeric formulae αβ, αβ, αβ, αβ, αβ, αβ, αβ) enables formulation of a model for PCC assembly. Our results suggest how multimerization regulates PCC enzymatic activity and showcase the utility of cryoEM in revealing the statistical mechanics of reaction pathways. |
External links | J Struct Biol X / PubMed:37128595 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.2 - 10.3 Å |
Structure data | EMDB-40472, PDB-8sgx: EMDB-40473, PDB-8sgy: EMDB-40474, PDB-8sgz: |
Chemicals | ChemComp-BTI: |
Source |
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Keywords | LIGASE / Multienzyme complex / carboxylase |