8ORB image
Entry Detail
PDB ID:
8ORB
EMDB ID:
Keywords:
Title:
24-meric catalytic domain of dihydrolipoamide acetyltransferase (E2) of the E. coli pyruvate dehydrogenase complex.
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2023-04-13
Release Date:
2024-02-07
Method Details:
Experimental Method:
Resolution:
3.25 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex
Chain IDs:A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U (auth: V), V (auth: W), W (auth: X), X (auth: Y)
Chain Length:249
Number of Molecules:24
Biological Source:Escherichia coli
Ligand Molecules
Primary Citation
Dimerization of a 5-kDa domain defines the architecture of the 5-MDa gammaproteobacterial pyruvate dehydrogenase complex.
Sci Adv 10 eadj6358 eadj6358 (2024)
PMID: 38324697 DOI: 10.1126/sciadv.adj6358

Abstact

The Escherichia coli pyruvate dehydrogenase complex (PDHc) is a ~5 MDa assembly of the catalytic subunits pyruvate dehydrogenase (E1), dihydrolipoamide acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). The PDHc core is a cubic complex of eight E2 homotrimers. Homodimers of the peripheral subunits E1 and E3 associate with the core by binding to the peripheral subunit binding domain (PSBD) of E2. Previous reports indicated that 12 E1 dimers and 6 E3 dimers bind to the 24-meric E2 core. Using an assembly arrested E2 homotrimer (E23), we show that two of the three PSBDs in the E23 dimerize, that each PSBD dimer cooperatively binds two E1 dimers, and that E3 dimers only bind to the unpaired PSBD in E23. This mechanism is preserved in wild-type PDHc, with an E1 dimer:E2 monomer:E3 dimer stoichiometry of 16:24:8. The conserved PSBD dimer interface indicates that PSBD dimerization is the previously unrecognized architectural determinant of gammaproteobacterial PDHc megacomplexes.

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