Prediction of the binding site on E1 in the assembly of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus.
The beta-subunit (E1beta) of the pyruvate decarboxylase (E1, alpha(2)beta(2)) 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 E1beta subunit and are consistent with thermodynamic evidence of a mixture of electrostatic and hydrophobic interactions being involved.
Jung
Hyo-Il
HI
Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
Perham
Richard N
RN
D000409:Alanine / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D019281:Dimerization; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity; D013816:Thermodynamics
D021122:Protein Subunits; D011768:Pyruvate Dehydrogenase Complex; D011994:Recombinant Proteins; D000409:Alanine