Mobility in pyruvate dehydrogenase complexes with multiple lipoyl domains.
High-field NMR studies were carried out with genetically-reconstructed pyruvate dehydrogenase (PDH) complexes of Escherichia coli containing from zero to nine lipoyl domains per lipoate acetyltransferase (E2p) subunit. The only significant differences between the NMR spectra were the increasing intensities of the signals derived from the lipoyl domains and their associated linkers, and the much enhanced signal from the E3-binding domain and its linker in complexes that are devoid of lipoyl domains. The results suggest an explanation for the presence of three lipoyl domains per E2p subunit in the wild-type PDH complex, based on its greater inherent mobility, and potentially more efficient active-site coupling, than any of the other complexes.
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, UK.
R S
RS
Machado
J R
JR
Guest
M P
MP
Williamson
D000123:Acetyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D051047:Dihydrolipoyllysine-Residue Acetyltransferase; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D011768:Pyruvate Dehydrogenase Complex; D000123:Acetyltransferases; D051047:Dihydrolipoyllysine-Residue Acetyltransferase