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Chain folding in the dihydrolipoyl acyltransferase components of the 2‐oxo‐acid dehydrogenase complexes from Escherichia coli
Author(s) -
Packman Leonard C.,
Perham Richard N.
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)80979-6
Subject(s) - dihydrolipoamide dehydrogenase , acyltransferase , pyruvate dehydrogenase complex , biochemistry , branched chain alpha keto acid dehydrogenase complex , dehydrogenase , chemistry , oxoglutarate dehydrogenase complex , dihydrolipoyl transacetylase , enzyme , stereochemistry , biology
The state of assembly of the pyruvate and 2‐oxoglutarate dehydrogenase multienzyme complexes was examined after the dihydrolipoyl acyltransferase (E2) component of each enzyme system had been subjected to varying degrees of limited proteolysis. Dissociation of the dihydrolipoyl dehydrogenase (E3) component accompanied specifically the excision of a homologous segment of each E2 chain that connects the N‐terminal lipoyl domain(s) with a C‐terminal catalytic domain. The latter remains aggregated as a 24‐mer and retains its capacity to bind the 2‐oxo‐acid decarboxylase (E1) component. The relevant segment of the E2o chain from the 2‐oxoglutarate dehydrogenase complex was isolated and shown to be a folded protein which still binds to E3.