title: Atomic structure of the cubic core of the pyruvate dehydrogenase multienzyme complex.
abstract: The highly symmetric pyruvate dehydrogenase multienzyme complexes have molecular masses ranging from 5 to 10 million daltons. They consist of numerous copies of three different enzymes: pyruvate dehydrogenase, dihydrolipoyl transacetylase, and lipoamide dehydrogenase. The three-dimensional crystal structure of the catalytic domain of Azotobacter vinelandii dihydrolipoyl transacetylase has been determined at 2.6 angstrom (A) resolution. Eight trimers assemble as a hollow truncated cube with an edge of 125 A, forming the core of the multienzyme complex. Coenzyme A must enter the 29 A long active site channel from the inside of the cube, and lipoamide must enter from the outside. The trimer of the catalytic domain of dihydrolipoyl transacetylase has a topology identical to chloramphenicol acetyl transferase. The atomic structure of the 24-subunit cube core provides a framework for understanding all pyruvate dehydrogenase and related multienzyme complexes.
authors.affiliation: Department of Chemistry, University of Groningen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Mattevi
authors.forename: G
authors.initials: G
authors.lastname: Obmolova
authors.forename: E
authors.initials: E
authors.lastname: Schulze
authors.forename: K H
authors.initials: KH
authors.lastname: Kalk
authors.forename: A H
authors.initials: AH
authors.lastname: Westphal
authors.forename: A
authors.initials: A
authors.lastname: de Kok
authors.forename: W G
authors.initials: WG
authors.lastname: Hol
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016948:Azotobacter vinelandii / Q000201:enzymology; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry* / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
chemical_list: D011768:Pyruvate Dehydrogenase Complex; D015500:Chloramphenicol O-Acetyltransferase