Dimerization of a 5-kDa domain defines the architecture of the 5-MDa gammaproteobacterial pyruvate dehydrogenase complex.
Sci Adv
; 10(6): eadj6358, 2024 Feb 09.
Article
em En
| MEDLINE
| ID: mdl-38324697
ABSTRACT
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 dimerE2 monomerE3 dimer stoichiometry of 16248. The conserved PSBD dimer interface indicates that PSBD dimerization is the previously unrecognized architectural determinant of gammaproteobacterial PDHc megacomplexes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Complexo Piruvato Desidrogenase
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Escherichia coli
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Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase
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Di-Hidrolipoamida Desidrogenase
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article