3RQC

Crystal structure of the catalytic core of the 2-oxoacid dehydrogenase multienzyme complex from Thermoplasma acidophilum

Summary for 3RQC

• Entry DOI: 10.2210/pdb3rqc/pdb
• Descriptor: Probable lipoamide acyltransferase (1 entity in total)
• Functional Keywords: alpha beta fold, acyl-transferase, transferase
• Biological source: Thermoplasma acidophilum DSM 1728
• Total number of polymer chains: 7
• Total formula weight: 178427.86

Authors

Marrott, N.L.,Crennell, S.J.,Hough, D.W.,Danson, M.J.,van den Elsen, J.M.H. (deposition date: 2011-04-28, release date: 2012-01-11, Last modification date: 2023-09-13)

Primary citation

Marrott, N.L.,Marshall, J.J.,Svergun, D.I.,Crennell, S.J.,Hough, D.W.,Danson, M.J.,van den Elsen, J.M.
The catalytic core of an archaeal 2-oxoacid dehydrogenase multienzyme complex is a 42-mer protein assembly.
Febs J., 279:713-723, 2012

PubMed Abstract: The dihydrolipoyl acyl-transferase (E2) enzyme forms the structural and catalytic core of the tripartite 2-oxoacid dehydrogenase multienzyme complexes of the central metabolic pathways. Although this family of multienzyme complexes shares a common architecture, their E2 cores form homo-trimers that, depending on the source, further associate into either octahedral (24-mer) or icosahedral (60-mer) assemblies, as predicted by the principles of quasi-equivalence. In the crystal structure of the E2 core from Thermoplasma acidophilum, a thermophilic archaeon, the homo-trimers assemble into a unique 42-mer oblate spheroid. Analytical equilibrium centrifugation and small-angle X-ray scattering analyses confirm that this catalytically active 1.08 MDa assembly exists as a single species in solution, forming a hollow spheroid with a maximum diameter of 220 Å. In this paper we show that a monodisperse macromolecular assembly, built from identical subunits in non-identical environments, forms an irregular protein shell via non-equivalent interactions. This unusually irregular protein shell, combining cubic and dodecahedral geometrical elements, expands on the concept of quasi-equivalence as a basis for understanding macromolecular assemblies by showing that cubic point group symmetry is not a physical requirement in multienzyme assembly. These results extend our basic knowledge of protein assembly and greatly expand the number of possibilities to manipulate self-assembling biological complexes to be utilized in innovative nanotechnology applications.

PubMed: 22188654
DOI: 10.1111/j.1742-4658.2011.08461.x

Experimental method

X-RAY DIFFRACTION (4.01 Å)