The β-subunit (E1β) of the pyruvate decarboxylase (E1, α2β2) component of the Bacillus stearothermophilus pyruvate dehydrogenase complex was comparatively modelled based on the crystal structures of the homologous 2-oxoisovalerate decarboxylase of Pseudomonas putida and Homo sapiens. Based on this homology modelling, alanine-scanning mutagenesis studies revealed that the negatively charged side chain of Glu285 and the hydrophobic side chain of Phe324 are of particular importance in the interaction with the peripheral subunit-binding domain of the dihydrolipoyl acetyltransferase component of the complex. These results help to identify the site of interaction on the E1β subunit and are consistent with thermodynamic evidence of a mixture of electrostatic and hydrophobic interactions being involved.
Bibliographical noteFunding Information:
This work was supported in part by a research grant (to R.N.P.) from the Biotechnology and Biological Sciences Research Council. We are grateful to the BBSRC and The Wellcome Trust for their support of the core facilities in the Cambridge Centre for Molecular Recognition. We thank the Cambridge Overseas Trust, the Department of Biochemistry and St John’s College, Cambridge for financial support to H.I.J.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology