1B5S: Dihydrolipoyl Transacetylase (e.c. Catalytic Domain (residues 184-425) From Bacillus Stearothermophilus

The pyruvate dehydrogenase multienzyme complex (Mr of 5-10 million) is assembled around a structural core formed of multiple copies of dihydrolipoyl acetyltransferase (E2p), which exhibits the shape of either a cube or a dodecahedron, depending on the source. The crystal structures of the 60-meric dihydrolipoyl acyltransferase cores of Bacillus stearothermophilus and Enterococcus faecalis pyruvate dehydrogenase complexes were determined and revealed a remarkably hollow dodecahedron with an outer diameter of approximately 237 A, 12 large openings of approximately 52 A diameter across the fivefold axes, and an inner cavity with a diameter of approximately 118 A. Comparison of cubic and dodecahedral E2p assemblies shows that combining the principles of quasi-equivalence formulated by Caspar and Klug [Caspar, D. L. & Klug, A. (1962) Cold Spring Harbor Symp. Quant. Biol. 27, 1-4] with strict Euclidean geometric considerations results in predictions of the major features of the E2p dodecahedron matching the observed features almost exactly.
PDB ID: 1B5SDownload
MMDB ID: 9599
PDB Deposition Date: 1999/1/10
Updated in MMDB: 2014/11
Experimental Method:
x-ray diffraction
Resolution: 4.4  Å
Source Organism:
Similar Structures:
Biological Unit for 1B5S: 60-meric; determined by author
Molecular Components in 1B5S
Label Count Molecule
Proteins (60 molecules)
Dihydrolipoamide Acetyltransferase
Molecule annotation
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Citing MMDB