T. Izard et al., Principles of quasi-equivalence and Euclidean geometry govern the assemblyof cubic and dodecahedral cores of pyruvate dehydrogenase complexes, P NAS US, 96(4), 1999, pp. 1240-1245
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
The pyruvate dehydrogenase multienzyme complex (M-r of 5-10 million) is ass
embled around a structural core formed of multiple copies of dihydrolipoyl
acetyltransferase (E2p), which exhibits the shape of either a cube or a dod
ecahedron, depending on the source. The crystal structures of the 60-meric
dihydrolipoyl acyltransferase cores of Bacillus stearothermophilus and Ente
rococcus faecalis pyruvate dehydrogenase complexes were determined and reve
aled a remarkably hollow dodecahedron with an outer diameter of approximate
to 237 Angstrom, 12 large openings of approximate to 52 Angstrom diameter
across the fivefold axes, and an inner cavity with a diameter of approximat
e to 118 Angstrom. Comparison of cubic and dodecahedral E2p assemblies show
s that combining the principles of quasi-equivalence formulated by Caspar a
nd Klug [Caspar, D. L. & Klug, A. (1962) Cold Spring Harbor Symp. errant. B
iol. 27, 1-4] with strict Euclidean geometric considerations results in pre
dictions of the major features of the E2p dodecahedron matching the observe
d features almost exactly.