4N72

Catalytic domain from dihydrolipoamide acetyltransferase of pyruvate dehydrogenase from Escherichia coli

4N72 の概要

• エントリーDOI: 10.2210/pdb4n72/pdb
• 分子名称: Pyruvate dehydrogenase (Dihydrolipoyltransacetylase component) (2 entities in total)
• 機能のキーワード: dihydrolipoamide acetyltransferase catalytic domain, pyruvate dehydrogenase, acetyltransferase, transferase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 82473.15

構造登録者

Chandrasekhar, K.,Arjunan, P.,Furey, W. (登録日: 2013-10-14, 公開日: 2014-04-23, 最終更新日: 2023-09-20)

主引用文献

Wang, J.,Nemeria, N.S.,Chandrasekhar, K.,Kumaran, S.,Arjunan, P.,Reynolds, S.,Calero, G.,Brukh, R.,Kakalis, L.,Furey, W.,Jordan, F.
Structure and Function of the Catalytic Domain of the Dihydrolipoyl Acetyltransferase Component in Escherichia coli Pyruvate Dehydrogenase Complex.
J.Biol.Chem., 289:15215-15230, 2014

PubMed Abstract: The Escherichia coli pyruvate dehydrogenase complex (PDHc) catalyzing conversion of pyruvate to acetyl-CoA comprises three components: E1p, E2p, and E3. The E2p is the five-domain core component, consisting of three tandem lipoyl domains (LDs), a peripheral subunit binding domain (PSBD), and a catalytic domain (E2pCD). Herein are reported the following. 1) The x-ray structure of E2pCD revealed both intra- and intertrimer interactions, similar to those reported for other E2pCDs. 2) Reconstitution of recombinant LD and E2pCD with E1p and E3p into PDHc could maintain at least 6.4% activity (NADH production), confirming the functional competence of the E2pCD and active center coupling among E1p, LD, E2pCD, and E3 even in the absence of PSBD and of a covalent link between domains within E2p. 3) Direct acetyl transfer between LD and coenzyme A catalyzed by E2pCD was observed with a rate constant of 199 s(-1), comparable with the rate of NADH production in the PDHc reaction. Hence, neither reductive acetylation of E2p nor acetyl transfer within E2p is rate-limiting. 4) An unprecedented finding is that although no interaction could be detected between E1p and E2pCD by itself, a domain-induced interaction was identified on E1p active centers upon assembly with E2p and C-terminally truncated E2p proteins by hydrogen/deuterium exchange mass spectrometry. The inclusion of each additional domain of E2p strengthened the interaction with E1p, and the interaction was strongest with intact E2p. E2p domain-induced changes at the E1p active site were also manifested by the appearance of a circular dichroism band characteristic of the canonical 4'-aminopyrimidine tautomer of bound thiamin diphosphate (AP).

PubMed: 24742683
DOI: 10.1074/jbc.M113.544080

実験手法

X-RAY DIFFRACTION (2.25 Å)