3B8K

Structure of the Truncated Human Dihydrolipoyl Acetyltransferase (E2)

Summary for 3B8K

• Entry DOI: 10.2210/pdb3b8k/pdb
• Related: 1EAA
• EMDB information: 1448
• Descriptor: Dihydrolipoyllysine-residue acetyltransferase (1 entity in total)
• Functional Keywords: central beta-sheet surrounded by five alpha-helices, transferase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 25938.16

Authors

Yu, X.,Hiromasa, Y.,Tsen, H.,Stoops, J.K.,Roche, T.E.,Zhou, Z.H. (deposition date: 2007-11-01, release date: 2008-01-22, Last modification date: 2024-02-21)

Primary citation

Yu, X.,Hiromasa, Y.,Tsen, H.,Stoops, J.K.,Roche, T.E.,Zhou, Z.H.
Structures of the human pyruvate dehydrogenase complex cores: a highly conserved catalytic center with flexible N-terminal domains
Structure, 16:104-114, 2008

PubMed Abstract: Dihydrolipoyl acetyltransferase (E2) is the central component of pyruvate dehydrogenase complex (PDC), which converts pyruvate to acetyl-CoA. Structural comparison by cryo-electron microscopy (cryo-EM) of the human full-length and truncated E2 (tE2) cores revealed flexible linkers emanating from the edges of trimers of the internal catalytic domains. Using the secondary structure constraints revealed in our 8 A cryo-EM reconstruction and the prokaryotic tE2 atomic structure as a template, we derived a pseudo atomic model of human tE2. The active sites are conserved between prokaryotic tE2 and human tE2. However, marked structural differences are apparent in the hairpin domain and in the N-terminal helix connected to the flexible linker. These permutations away from the catalytic center likely impart structures needed to integrate a second component into the inner core and provide a sturdy base for the linker that holds the pyruvate dehydrogenase for access by the E2-bound regulatory kinase/phosphatase components in humans.

PubMed: 18184588
DOI: 10.1016/j.str.2007.10.024

Experimental method

ELECTRON MICROSCOPY (8.8 Å)