8ORB

24-meric catalytic domain of dihydrolipoamide acetyltransferase (E2) of the E. coli pyruvate dehydrogenase complex.

Summary for 8ORB

• Entry DOI: 10.2210/pdb8orb/pdb
• EMDB information: 17119
• Descriptor: Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex (1 entity in total)
• Functional Keywords: pyruvate dehydrogenase complex, pdhc, e2, cryo-em, transferase
• Biological source: Escherichia coli
• Total number of polymer chains: 24
• Total formula weight: 659785.18

Authors

Zdanowicz, R.,Meinhold, S.,Glockshuber, R. (deposition date: 2023-04-13, release date: 2024-02-07, Last modification date: 2024-02-21)

Primary citation

Meinhold, S.,Zdanowicz, R.,Giese, C.,Glockshuber, R.
Dimerization of a 5-kDa domain defines the architecture of the 5-MDa gammaproteobacterial pyruvate dehydrogenase complex.
Sci Adv, 10:eadj6358-eadj6358, 2024

PubMed Abstract: The 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 (E2), we show that two of the three PSBDs in the E2 dimerize, that each PSBD dimer cooperatively binds two E1 dimers, and that E3 dimers only bind to the unpaired PSBD in E2. 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.

PubMed: 38324697
DOI: 10.1126/sciadv.adj6358

Experimental method

ELECTRON MICROSCOPY (3.25 Å)